Tequila Sunrise
Adventurer
I like elegant and consistent mechanics that commit to a goal. So I love 4e's original AEDU structure, for creating a consistent commitment to PC-PC balance, tactical gameplay, and interesting character options.Also what is everyones favorite "mechanics" in the RPGs they like.
I also love 3e's a la carte style multiclassing -- in concept, if not completely in execution -- for being a (conceptually) elegant compromise between a class-and-level based system and a point-buy system. Making it work well is somewhat of a holy grail of mine.