I was resisting the urge to post in this topic, but now I think I'll indulge my OCD list-making tendencies...
Fallout
Fallout 2
MechWarrior 2
MechWarrior 2 Mercenaries
Tetris
Super Mario Bros. 3
Super Mario 64
Super Metroid
Doom (I'm including things like Final Doom, Doom 2, The Ultimate Doom in this)
Raptor: Call of the Shadows
Tyrian
1943
Ratchet and Clank 2: Going Commando
Grand Theft Auto 2 and 3
The Elder Scrolls 2: Daggerfall
The Elder Scrolls 3: Morrowind (especially with Tribunal, Bloodmoon and a few mods installed)
The Legend of Zelda
The Legend of Zelda 2: Link's Adventure
The Legend of Zelda: A Link to the Past
Faxanadu
Mega Man 4
Tony Hawk's Underground 2
Final Fantasy VI
Secret of Evermore
Secret of Mana
Chrono Trigger
NetHack
Earthbound (can't believe I nearly forgot this)
There are some that I would like to add to the list but simply have not played enough to be able to rightfully list here - Seiken Densetsu 3 is a game I would LOVE to have more time with, as well as Ikaruga and Mother 3 - and some I simply can't quite remember (but still ate up LOTS of my free time).