What's a minor ability that would be an awesome dip if could get it for "something"

[Tetrasodium]

There are twelve classes & umpteen races. I'm working on something that would give players minor awesome things based on stuff like race & homeland (ie gnomes from X can learn ritual spells of level/3 from any class spell list if they come across them, elves from Y start with superiority dice & the parry maneuver, goblins from Z get defensive duelist & can treat light weapons as finesse, Bugbears from Z can add +1 to their bard levels for figuring their bard cantrips/spells known & spell slots, Q has compulsory military service & everyone from there has a martial weapon proficiency plus either medium armor proficiency or medium armor mastery, etc). While some are indeed capable of being powerful, most just reinforce lore in a way more practical than "gnomes are good wizards so get +1", so I'm looking for some abilities (potentially from other classes)

What are some abilities that many classes could steal from another class or part of a feat to either open a wildly different door or provide a very noticeable benefit on par with the benefits of v.Human?


Barbarian
Bard
Cleric
Druid
Fighter
Monk
Paladin
Ranger
Rogue
Sorcerer
Warlock
Wizard


It's especially useful if they are things that you could easily get, but generally would never get due to the opportunity cost or because getting to them would derail a concept to far from taking a dip a level or two too far

[Easy_Lee]

The shillelagh cantrip from druid is extremely useful for a ranger and fairly useful for a low level monk. On ranger, it opens up a SAD melee option.

Reckless Attack from Barbarian 2 is useful enough on melee builds that some fighters dip just to get it.

Rogue cunning action is useful to just about anyone.

Warlock invocations, depending on what's allowed, are easily worth a feat. Most rogues and shadow monks would be happy to burn a feat for Devil's Sight.