Anachronox, the "other" Ion Storm game, has not been mentioned enough times in this thread already. It's on Steam, too!
Designed by Tom Hall (the other big Ion Storm developer from id, responsible for Commander Keen among other things), it's a turn-based RPG inspired by the likes of FFVII. It kind of feels like the whole thing is being desperately held together by hope and a prayer, and it finishes off with a bit of a non-ending, but it's a unique little twist on the genre and some of the writing is quite clever.