KiNgBrAdLeY7: The Suffering collection. Those are excellent good old games and they have aged exceptionally well! Why they aren't here already, is one of those huge mysteries of mankind and all.
I think you can still get the first one free, I did some time ago and I believe I still have the digital copy Midway gave away for free too. It doesn't have the GOG touch though. If you don't have it or can't find it I can try to find a way to share it. But it's 1.3GB, I can't imagine it would be too hard to find though.
Dungeon Siege series is the only one I can think of at the moment.
Maybe Diablo 1 and 2 with expansions to both. Although if I remember correctly, blizzard didn't make the expansion for the first Diablo. I think Sierra made it.
Civilization series, 2 in particular with expansion packs. I played the first one on SNES for a long time until I found 2 for PC and loved it. Never played any of the others afterwards though. I still have them, as well as the SNES version on my cell phone for when I'm waiting around I play a couple rounds.
Parasite Eve series (Including 3rd Birthday). Loved those games. Gran Turismo series too while I'm on console games.
And Shadow Tower, Xeno Gears, Final Fantasy VII, Chrono Trigger. ALL of the Silent Hill games.
Land of the Dead - Road to Fiddler's Green. I know it had extremely bad ratings but I loved it. It was simple and effective and runs on the UT engine.
After seeing Quake and Doom, I'm kinda hoping for Hexen also.
And last but not least, Project Zomboid