For me it is definitely a Thief. For a simple reason that it fits the character I RP the best. Plus mechanically, Thief has one of the best subclass abilities in the game.
Second would be Way of Shadow. Tons of flavour, and also super effective mechanically. Can’t go wrong if you like martial arts, stealth and ninjas.
Third one is Oath of Vengeance. So much RP potential. A Paladin on a quest for revenge… just amazing.
