God Mutant League Football and Hockey are must plays for classic sports games. I don't know if you're into patching games, but I'd highly recommend the Final Fantasy games that never made it here for nes and snes. Also Dual Orb 2 was good as well.
There's some other series like Langrisser which is an rpg series. Star Ocean for snes is great as well. Truly a shame it never made over here back in the day.
I'll just give a basic list I guess other then the ones mentioned.
SNES: Front Mission, Ogre Battle, Knights of the Round, Lennus 1 and 2, Seiken Densetsu 3, Everquest, Starfox, Star Wars games, Tales Of Phantasia, Castlevania, Super Metroid, Legend of the Mystical Ninja *also had a n64 game*, Bases Loaded, Brawl Brothers, Rival Turf, The Peace Keepers, Earth Defense Force, Ignition Factor, R-Type.
Genesis: Phantasy Star 2, 3, 4, Shinning Force 1 and 2, Eternal Champions, Streets Of Rage, NHL 93 or 92, Warsong/Langrisser, Another World, Flashback, ESWAT, ECCO, Ghouls and Ghost.
N64: Mystical Ninja, Operation Winback, Zelda.
PS1: Chrono Cross, Tales of Destiny, Star Ocean, Lunar 1 and 2, Bushido Blade 1 and 2, Battle Arena Toshinden 1 - 3, Breath of Fire 3 and 4, Castlevania Symphony Of The Night *probably the best of all the games*, Fade To Black *the third in the another world/flashback series*, Front Mission 3, Grandia 1, Ehrgeiz *kind of a crazy fighting game* Tony Hawk's Pro Skater 2 or 3.
Hope that helps man.