I decided to mix things up a bit. The pacts that patrons make with warlocks are not by type of patron but by type of pact. Each pact is most commonly associated (in the minds of the commoners) with a type of patron, but not all patrons fit the type.
These are designed as illustrative, not comprehensive examples of patrons. No demonic patrons are listed, because demonic pacts are wholly unsuitable for adventurers as they carry with them an automatic death sentence throughout the Federated Nations. The alignment notations are intended as broad roleplaying hints, not restrictive definitions.
Fiend Pact
Not all beings that count as Fiend patrons are actually fiends. In fact, many fiends will not make such a pact; many that do are not fiends at all. The most common characteristics of those that enter into a pact as a Fiendish patron are the associations with fire, destruction, and a desire for power over others. Fiend pacts are what most think of when they think of pacts at all. They usually involve a strict, written contract with penalties for non-performance or forfeiture and clear details about what each side promises.

Caporegime Xe’ka’Ala (neutral evil)
This ambitious devil of Family Ala is striving to rise through the ranks. He favors those who bring down his foes, provide wealth (especially in soul energy), and those who encourage others to make pacts with him or with his underlings. His contracts are always narrowly-worded and he never lets anyone get away easily. He has been known to “reinterpret” contracts that he believes are losers for him. Caveat Pactor. He does not particularly care about the means used, as long as they don’t backfire on him. Those who break their pact will likely be ignored, unless they sell secrets to his enemies.

Underboss Xa’seka’barong (neutral good)
Xa’seka, second-in-command of the Barong family, hates demons. She’ll grant power to those who pledge to eradicate demons, demonic cults, and all abyssal-touched beings from existence wherever they are found. She does have high standards, though. Only those with promise are worthy of her blessing. She will keep her bargains, as long as the warlock keeps his. Siding with demons, even briefly or in opposition to a larger foe, will cause her to consider you an enemy no better than the demons themselves. Her servants will attack without mercy, and forgiveness is not possible under normal circumstances. She is unlikely to hunt you down, however.

Flamelord Icalonth (chaotic neutral)
This prince of efreeti likes nothing more than to spread “freedom” (as he calls it) everywhere. His “pacts” are really nothing more than grants of power to individuals who he believes will break down order, destroy governments and institutions, and generally spread anarchy and hedonism throughout the Mortal plane. Or to those that simply amuse him in some way—he is nothing if not capricious. While not actively malicious, he and those pledged to him despise all concepts of restraint. What they want, they take or do. As like to help as to harm, servants of the Flamelord do not form cults or organized worship organizations. Each additional bit of power from the Flamelord comes when the seeker shows the “freedom” they’ve wreaked. He doesn’t really care what contractors do, as long as it’s what they want to do.

Slavelord Xel’aka’Zagan (lawful evil)
As third in command of the Zagan family of Chou, Xel’aka is a powerful, tyrannical devil. He favors those that will worship him and accept him as their ruler and pay homage in tithes of their anima. He commands his followers to form cults and actively proselyte to others. Oppression and enslavement are the fates reserved for those that will not bend willingly. He gives power to crush enemies and bind all into subjugation. He despises Flamelord Icalonth, family Aeshema and all other lovers of “freedom” as weak-willed and unworthy and commands his followers to oppose them even to violence.

Ulok’ka’Kroni (chaotic evil)
This devil, also known as “Havoc’s right hand”, delights in destruction. It doesn’t matter what, or whom. Burn, kill, destroy. Contacting it is usually done over the bodies of those slain in bloody battle, and it rewards those who share its goals.

Saela’il’Allocer (neutral)
Saela is a contractor for family Allocer. Once an aelven wizard, Saela gave up her mortality to become a fiend. She is known as “the seeker of lost magics”—her primary desire is to uncover or discover arcane magic now lost or unknown. She makes pacts for this purpose, in exchange for a share of anything uncovered. Her warlocks are often part of the Imperial Sons research order, known for their flexible ethics on matters of arcane research.

Archfey Pact
As with the Fiend Pact, fey are not the only patrons who make this style of pact. Unlike the fiend pact, which is very quid pro quo, those that form the Archfey pact tend to be more capricious and arbitrary with their pacts. For most of the fey Patrons, they wish to experience life and emotions through their clients’ senses so as to understand mortals more. As such, they may require that the client send them (in dreams or otherwise) their experiences periodically. Others may wish the client to promote the emotional nexus with which the fey is obsessed. In some cases, this is benign; others are malevolent or harmful.

Of the Courts, the Summer and Spring Courts tend to form these pacts most frequently, but they’re very different in their attitudes toward the pacts. Pacts with Spring patrons are often done on a spur of the moment basis by the Patron, with little thought for the future. Sometimes, these pacts are formed without specific intent—the Patron considers the granted powers either a joke (to see what mortals will do with sudden power), a reward for some act (which the client may not even know they performed), or even a punishment (often for someone else’s actions entirely). Summer patrons usually demand more tangible service or are repaying debts.

Non-fey patrons are more likely to focus on a specific portion of the pact, but all tend to be nature-aligned, “light” beings. Devils of Mara-deva families frequently also form this pact.

Niamh of Flowers (Chaotic Neutral)
This Spring Court noble is known to be fascinated by cities and elves and especially by fancy parties. Those she deems “beautiful” enough may be presented with a bouquet of enchanted flowers from her garden. Flighty, fickle, and vain, she loves nothing more than to be flattered and complimented. She tends to form pacts easily (always with elegant, well-dressed people of either sex) and forget them just as suddenly. While her primary home is in Shadows (in the City of Mirrorholm), she can be found in disguise as a surprise guest at many an elegant party, especially in Kaelthia. Her pacts are not incredibly onerous; the only thing she cannot stand is physical ugliness. Disfiguring scars or twisted abominations (especially those associated with the Twisted One) draw her ire.

The Dancer in the Dark (Chaotic good)
A demigod in service to Aerielara, Lady of Jewels, the Dancer is a patron of sensuality and seduction. Commonly depicted as a lithe, naked (or clad only in a diaphanous slip) woman with either feline and ophidian features (varying by depiction), she is revered most heavily in the Stone Throne. Many of the temple dancers there treat her as their Patron; some receive power from her. Charm and subtlety are her hallmarks. Her warlocks are often spies and agents. She asks that they liberate the captive and overthrow slavery (sexual slavery or oppression are particular hatreds of hers) and spread pleasure wherever they go. She is angered when her clients abuse the power granted to them to take unfair advantage of others or cause misery among the innocent).

Luagh Lawgiver (Lawful Neutral)
Luagh is a powerful Summer Court fey who is active in Byssia. Unlike most fey, he is orderly to a fault; he will not break a sworn oath or twist words. A bit of an outsider at Court, he doesn’t participate much in the status games there, preferring to work among mortals. He is known for being completely impartial. His pacts are with those that share his views and pledge to work to bring order and justice to the world wherever they may roam. He prefers peaceful means but is not averse to violence if necessary.

Caporegime Ioleth’al’Beleth (chaotic neutral)
A ranking devil of Beleth, the family associated with music, Ioleth’al is a common patron for those who wish to join bardic magics with more pact-based magics. She seeks to expand the reach of harmonies and to discover new ways of melding music and magic. She opposes those that would lock song and magic behind barriers (either physical or cultural). All songs must be sung, she commands her servants. All minds must be touched.

Great Old One
Those that form this pact are frequently the most alien beings known. In many cases, this is not even a true pact. Some patrons choose their contractors, touching their minds for inscrutable purposes. Some observe the Mortal realm through their clients’ eyes. Others are seemingly unaware of the pact itself. The least predictable of the pacts, these patrons run the gamut from beings Beyond to deep-sea entities. Devils of Leiutis are among the most common patrons of this pact, although they also form the Fiend pact.

Leviathan (Neutral)
Leviathan is one, and Leviathan is many. All the great beasts of the deep oceans are tied into a single creature, the oldest living being on the Mortal plane. While its constituent bodies may die or go rogue, the singular entity remembers the Dawn War. It sings its memories back and forth across the globe, continually reminding itself of what it knows. It sees its sole purpose as being the living memory of the universe. It seeks to learn and to know all that transpires. Of all the Great Old Ones, it is the most active in the Mortal realm, making pacts with sea travelers and those it resonates with. Its clients spread out and act as its eyes and ears. They are not sworn to non-interference—their “interference” is also part of the memory being created. The only demand Leviathan makes is that its clients act to preserve knowledge wherever possible.

Valeria (Neutral Good)
Not much is known for certain about this denizen of the Great Beyond, other than that she takes the form of a gigantic nautiloid. Vassarian Kabir, one of the Catalysts, has been quietly teaching select people in the Order of the Seeking Tentacle to contact her to form pacts of service. In this pact they swear to defend the Mortal plane against all threats from Beyond, specifically the Awakener in all its forms. As a pre-requisite to forming this pact and gaining power, they pledge themselves to uphold the Federated Nations and the Adventurers’ Guild more specifically and to seek out worthy candidates and to purge those that threaten the stability of the Council or the Guild.

Chief Scholar Kal’eg’Orobas (Chaotic Neutral)
Head of family Orobas, Kal’eg is the best spy in the Astral Plane. His mission is to discover secrets. Wherever, and of whomever they may be. Unlike the Grigori of Thoraz, the Orobas don’t blackmail others with this knowledge. He simply wishes to make all secrets known. He opposes the Family Phenex (who seek to conceal truth).

Celestial Pact
Probably the most common pact, this pact is formed between one of the demigods or ascended heroes and a mortal sworn to their service. Unlike the other pacts, there is little to no stigma associated with this pact. As a matter of fact, Celestial Warlocks are the main “clerical” spell-casters in both Byssia and the Stone Throne.

The Queen Ascendant (Lawful Good)
Until 205 AC, the Queen was a living being who occupied the throne and was the centerpiece for the worship of the residents of the Stone Throne. Worshiped as a god in flesh, the daughter of Roel Kor and Aerielara, she was a high elf whose birth pre-dated both the Cataclysm and the Fall of Empire. Her position was, to some degree, a lie. She was the instrument of a pact with the White Skull to feed an entire country worth of souls, sacrificed in her honor, to slake his demonic thirst. Forced into service as the linchpin of that pact by her father, the Queen had suffered for more than 800 years. When the Catalysts destroyed the anchor stone that prisoned her and commanded her obedience in 205 AC, she was freed. Using the remains of the souls that had passed through her and the worship of a nation, she transcended death and became an ascended hero and the patron of a nation.

She commands her warlocks (among whom are most of the supposed clerics of the nation) to foster order and to purge demon worship. Her dogma is caste-oriented, with the nobles at the top to direct the judicial and administrative affairs of the people and to protect them, the tradesmen and skilled workers in the middle to direct the commerce and growth of the people, and the commons at the base to support the others in their efforts (and to be supported in turn). The priests watch over the spiritual and moral well-being of the people. In principle, the priests have the final say, but that is vestigial at this point.

The Honored Ancestors (Lawful Good)
The collective group of ascended heroes and ancestral figures from the nation of Byssia are the Honored Ancestors. Individual members may make pacts with their descendants, but the group, as a whole, pacts with shrine keepers and firekeepers primarily. It commands its followers to protect the sacred shrines (both their own and those of the kami), to honor the traditions of the people, and to protect the people from threats internal and external.

The Left and Right Blade (Lawful Evil)
Two beings serve the Hollow King. Titled his Blades, they are mysterious figures who act in tandem. They are the active divine figures in the Blackened Dagger, the assassin priests of the Council Lands. Many of their pacts are with assassins, but they have been known to empower those driven by revenge or those who seek to bring down those who the law cannot touch. No means are off limits to those who swore pact with the Blades. If achieving the desired ends hurts others, so be it. The pact is to be “both judge and jury, thief-taker and executioner, to be the law where the law cannot be.” They consider themselves to be gardeners, pruning back the trees so that they can flourish. Disease must be rooted out, corruption excised, and even healthy branches trimmed if they threaten the balance of the whole. On the other hand, the weak branches should be strengthened so that all may bear fruit for the gardeners.

Those that form the Hexblade pact tend to be of two types. First are the artificers, those who create powerful and intelligent items and hand them to mortals to observe their development. Second are those items who have become intelligent in and of themselves.

Redemption (Neutral Good)
This blade once served the angel who protected Malek’s Tower in Luca before the Cataclysm. When she was deceived into falling from her duty and then redeemed and ascended as one of the Wings of Mercy, the blade took on itself all her scorn, self-hatred, and desire to be reborn. Awakened to intelligence, it slipped into shadow. Subsequently, mortals who wished to give up their old lives might find themselves visited by a strange shadow, wielding a glowing blade. It offers absolution and oblivion, in exchange for service. Redemption desires his servants, who abandon their previous lives and names when they take up the symbol of the blade, to go forth and divide the repentant from the impenitent. It commands them to wield power to take their sins away and to bring the obdurate to the dust. If they repent, they are forgiven and washed clean. If they do not, their sins will be covered in their own blood.

The White Raven (Neutral)
Not much is known about this figure. It appears as the titular figure (a white raven with silver eyes) in dreams to some who desire power (for whatever end) and offers them a pact. It offers an object—a rod, a blade, an orb, a necklace. Something. This item empowers the warlock, teaching them to wield power. The object cannot be abandoned, but the White Raven makes no other demands. Some believe that it watches the world through the pact objects; others claim more sinister designs.