Indeed, this question has been posted before.
I don't play much games anymore, but when I do:
On my PS: Metal Gear Solid (This is really one of the best games available, I've played it to the end at least 15 times and still I'm not getting sick of it), Tony Hawk's proskater 2, Gran Turismo 2. The pc game I like the most has to be Unreal Tournament.