Posting in a "games as art" thread.
Simple answer: All games are art; it's just that most aren't particularly GOOD art. That said, I'm a bit of a connoisseur of artsy games. If you've already played the Team ICO games, Rez, and Katamari, I'd check out, in rough order:
1) Planescape: Torment. The closest thing to a Citizen Kane that the video game industry has ever produced. Simply amazing in every way conceivable.
2) Killer7 and No More Heroes, and possibly Contact. Suda51 has a reputation for developing bizarre, post-modern games, and it's a reputation well deserved.
3) Silent Hill 1-3. All three are worth playing, and all of them are disturbing in a David Lynch's Eraserhead sort of way.
4) Shin Megami Tensei: Nocturne. I can't think of very many JRPGs that are worthy of the title "artsy," since the genre is largely crap, but this one definitely is. (As a bonus, it's also one of the best JRPGs ever made.)
5) Any of the Oddworld games, but especially Abe's Odyssee and Exxodus on the PS1. Bizarre puzzle/platformers that are well worth playing.
6) Fear Effect 1 & 2. Sort of Resident Evil crossed with Blade Runner, as odd as it sounds, and one of the few games out there that would probably make a good movie.
EDIT: You may also want to watch out for Eternity's Child, a hand-drawn platformer coming to Nintendo's WiiWare service. Ever since finding out about it and seeing some screenshots, it's been up there on my "most anticipated titles of 2008" list.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
