The N64 Castlevania was fun, I think. That was years ago, though. Dreamcast: Armada (some fun co-op!), Skies of Arcadia (although the 'Cube port is much more friendly to people that detest random battles), Rayman in general
Link to the Past (SNES)--my favorite Zelda, followed by Ballad of the Windfish. Chrono Trigger (SNES)--a JRPG with some nice battle twists (for its time) and a decent, if somewhat confusing, storyline. Um... Hrm...
Gauntlet for all your mindless shitty fantasy, instant action, co-op desires. Lots of fun with that with friends. I still play Dark Legacy on the Gamecube every now and then with friends, siblings. Good times. Pizza is a good compliment to a night of it.