Hmmm... my most commonly performed would probably be the basic stuff you learn just starting out (tyvm Brad Christian). So, not including those obvious routines like ACR, 2CM, Biddle, etc., then a couple are (in no particular order):
Half vanish, DM - very recently saw it & realised how cool it looks
Card to pocket - usually I cop it though, my classic palm sucks
Hand to mouth, D&D - scares the hell out of people
Random card force/prediction/mind reading - always worth a try
Gambling routine