[PC] What is your Favorite PC game EVER?

I've also played a MMORPG for quite a long time now (FFXI), but I really can't say it's the best game I've ever played, though it would probably be the one I've played the most.

The Fallout games (1 and 2) are probably my favourites. The setting is just absolutely dead on, and I love the fact that it doesn't hold back on the "mature themes". Don't get me wrong, stuff like that doesn't make a game great, but it can certainly add a lot when it's used in the right way.
Fallout does just this, and it feels completely natural within the world of the game.
It's also perhaps the best games I've played when it comes to the roleplaying. In this game I feel like I really have choices. I really like Baldurs gate and the Elder Scrolls series as well, but if it's roleplaying I want, Fallout is definetely the winner.

I also love the sheer volume of different random encounters. Playing this game for the first time (I played 2 first), it was actually quite scary to travel the wastes because it's really dangerous (especially playing it for the first time)! But you can also encounter merchants and so much other stuff... It's really awesome.
These games are not perfect, but the scope and the sheer volume of stuff there is makes them a true winner for me. Awesome games.

I'm just now playing Arcanum, which is reminiscant of the Fallout series in that it's quite a good roleplaying game. I'm really enjoying it (is has a rather unique setting to), but it doesn't quite reach the wonder of Fallout. Still a very good game that I'd recommend to anyone that likes Fallout.

How ya doing, buddy?