i have it for the pc (finished my first run through today as a soldier, fun) and it is really good. No lag, fantastic story, interesting side quests and good combat, with a whole load of weapons...though they are all more or less the same. i plan on playing through it many more times as i wait for Left 4 Dead to come out. BTW, what is the GLaDOS voice that is saying "who are you?" to me occasionally?