Undrave
Legend
Which one would you say is the most fun, even if it's not as good?Frankly, the best single out-of-combat feature is spellcasting. Which is also the best single in-combat feature.
Reliable talent is the runner-up. It doesn’t give you as many easy ways to avoid having to make checks as spellcasting does, but it’s incredible insurance against failure on checks, especially when combined with expertise.
Wild Shape is potentially very powerful out of combat, depending on what forms the DM will let you access.
Honorable mention to Jack of all Trades - Reliable Talent’s less successful older sibling.