Anachronox is really good, it's like a western JRPG and it's got that Tom Hall Humor. Be sure to turn vsync on through nvidia options, otherwise the camera transitions are painfully long. Keep in mind that it runs on the Quake II engine, which was already pretty old at the game's release, so don't expect anything stellar with the graphics. The game's strengths are characters and writing.
Also, get Descent.