Artificer - Armorer. I like its ability to tank and has some interesting powers. But not a big fan of Artificer as a whole because they are disappointingly weak.

Barbarian - Ancestral Guardian. Love the concept of spirits helping and being tanky and defending others is a play style I like.
I also like the Wild Magic Barbarian. Having random effects allows for differences with each rage and working out the best way to use whichever one you end up with.

Bard - Sword is pretty stylish and Eloquence is very powerful, but generally not a fan of playing bards myself, although I like having one in a party.

Cleric - Tempest. It is great for a front line Cleric and can be good with blasting to. Order Cleric is my favourite for a support/back line cleric, especially if you have a Rogue and paladin to give attacks to.

Druid - Moon Druid. I like transforming and fighting as a beast.

Fighter - Rune Knight. I love the concept of Rune magic and also becoming large is great so I love this subclass. Also it gives passive benefits that help the fighter out of combat. The Echo Knight is a close second. The concept is amazing. It is a pity that it doesn't have better rules (being an object is bad and it should be able to fly/hover if the fighter can't, because conceptually it is an alternative time line version of the fight).

Monk - Not a big Monk fan, they are a big weak. But I like the concepts of Shadow and Astral Soul Monks.

Paladin - Ancients has a great aura. Watcher is a great concept and has is really good against certain types of enemies.

Ranger - Drakewarden. I love having a Draconic pet. I have recently finished a campaign playing a kobold warrior with a pet Drake. It was a fun character to play.

Rogue - Arcane Trickster. Magic adds a lot of versatility and power to the Rogue. I also like the concept of the Soul Knife and it has some great powers but the soul blades need to work with extra Attack and reaction attacks.

Sorcerer - Divine Soul is pretty good. So is Shadow Soul.

Warlock - one of my favourite classes. I have played a Goblin Celestial Warlock from 1-20 Lvl. The healing is great. I also love the Hexblade although I don't like that it is so good for multiclass dips. I also like both the Genie and the Undead warlocks and want to play them in a campaign at some point (I have played a Undead Warlock/Moon Druid in a one off, becoming an undead bear. I want to play this concept for a longer game.)

Wizard - Bladesinger wins it for me but it is a bit too powerful and would prefer it to be more balance. My favourite type of character is a Gish, and Bladesinger is a powerful magical warrior while being a full wizard if they want to just relie on magic. I would prefer a Swordmage class that combines magic and martial might.