[PC] What is your Favorite PC game EVER?

I got way too many favourites to pick just one, so here's a small selection:

Beyond Good & Evil
They just make too little games like these anymore. Captures the spirit of good old adventuring perfectly and molds it into a fantastic modern action/adventure. It has charm and atmosphere like no other. Sorely overlooked.

Full Throttle
One of LucasArts' most fantastic adventure games EVER. I love the rough-and-rowdy action movie atmosphere, especially during the climax. Not to mention Mark "Luke Skywalker" Hamill voices the villain. And the music just plain ROCKS.

Gabriel Knight: Sins Of The Fathers
Sierra's best. I love how the story blends fact and fiction, plus it fleshes out Voodoo beyond the usual dolls-and-pins stuff. Logical, tricky and fun to solve puzzles and FABULOUS music make this is an utter joy to play. Same goes for the sequel (and the switch from pixel art to live action was a master stroke, especially since they handled it so brilliantly, minus the casting of Dean Erickson as Gabriel).

Half-Life
Redefined single-player FPS and still has one of the largest mod communities in existence. The atmosphere and presentation of the game was and still is unbeatable.

Jam it back in, in the dark.