Sega:
-Quackshot (had Donald Duck in it, was a quality game as a kid)
-Toe Jam and Earl (catching humans in jars on a space planet - fun as a kid, but funny to bust out now after a smoke, funny music and scenery)
- Sonic 1 and 2. Didn't like Knuckles coming into it after 2 :P
PS2:
-GTA San Andreas, Vice City, and GTA 3 - all ground breakers for their time.
-Pro Evo 6, and I also liked 2010....that was apparently one of the worst? I enjoyed it anyhow.
-Fight Night. Can't remember which, but it had Ricky Hatton in it and was a top game, released around 2005 I think? Good multiplayer too.
I notice a few people on here enjoyed 'Zelda: Ocarina of Time'. DON'T BOTHER WASTING YOUR MONEY ON THE DS VERSION! The exact same one is easily downloadable for PC, anyone wants info on how to get it, PM me.