I admit i'm a lazy bastard, so if these have been mentioned already here, somebody give me a kick on the ass.
Kirby's adventure, especially the NES version. All though the GBA re-make is not that different, i prefer the original. I even own it IRL, i just have no clue where i've lost the cartridge.
Then there are the Castlevanias. I own Simon's curse my self. Then there is Duck Hunt. On a emulator, it's a complete waste of time, but with the actual zapper, it's way more fun.
Then there's the Nintendo World Cup soccer game. The best soccer game. EVER!
Then we leave the NES territory for now and enter PSX world. First three Tekkens, ah so good. Crash series (Sierra ruined it, hang them!), Spyro-series (haven't played these new ones...), then there was a sort of a physics puzzle game, Kula World. And then there were Twisted Metal games... And the two games where you play as a skeleton (forgotten the series name)...
And Soul Reaver. I love that game.