Jesus, I got a lot to name, so here goes.
The Half-Life series, including the two expansions for HL1.
StarCraft series.
Diablo Series.
WarCraft series. (Hell, pretty much any game with the name Blizzard name on it)
FreeSpace 1 & 2.
Mortal Kombat 1, 2, 3 and Deception.
Command and Conquer series.
Brothers in Arms, Call of Dut, and Medal of Honor Allied Assault (I can't decide between the three)
KOTOR 1 and 2.
Jade Empire.
Fallout series.
Total Annihilation series.
Baulders Gate series.
IceWind Dale series.
Star Trek: Elite Force.
Monkey Island series.
Full Throttle.
Sam and Max.
Beyond Good and Evil.
MechCommander 2.
Dark Forces/Jedi Knight series.
X-Men Legends.
Twisted Metal Series.
Burnout 3.
Gran Tourismo series.
Splinter Cell series.
Super Mario series.
Final Fantasy 6, 7, and 10.
Deus Ex series.
System SHock series.
MechWarrior 3 and 4.
Homeworld series.
MarioKart.
Killer Instinct.
NFL 2k series.
That's it for the moment, heh.