Ultimate Mortal Kombat 3 is the greatest game of all time.
Agreed - well, best fighting game anyway

Everyone seems to prefer MK2 (once had a friend jokingly tell me we probably shouldn't be friends anymore if I don't think MK2 is the best Mortal Kombat!), but I've always prefered the speed and game play mechanics of MK3/UMK3. Miss Johnny Cage, Baraka, and Raiden though.
Other than that, I love KI 1 and 2, SFII series, SFIII, and to lesser extents SFA, SFEX, Tekken, and Virtua Fighter series. Never really got into any others - most of the others I've played are just laughably bad or cheap clones of one of the aforementioned games - but my interest in seriously tackling new games really dropped off from the late '90s onward, so I may have missed out on some stuff I would've liked, I dunno.