PC
BioShock
The Witcher
Beyond Good and Evil
Assasin's Creed
Empire: Total War
Rome: Total War
GRAW
GRAW 2
Ghost Recon
Ghost Recon: Desert Siege
Ghost Recon: Island Thunder
GTA
GTA 2
GTA 3
GTA: Vice City
FarCry 2
Heroes of Might and Magic V
Xbox 360
Mass Effect (I would probobly play it more if i had it on pc in stead of xbox... i don't really play xbox any more)
Mirror's Edge (yeah i know, it's like 8 hours long, but i've still only done half of it)
I have a problem with not finishing games. I'm determined to get through The Witcher and Bioshock, but then Team Fortress 2 and Civ 4 are next on the list, i'm not so diligent.
But it's not that i neglect every game i buy. I recently finished Darwinia and all the HL2 games, and have been playing The Movies quite a bit.