Must Buys:
1) The Legend of Zelda: Twilight Princess
Duh. I've never played a bad Zelda game (hell, I haven't even played a middling Zelda game), and this won't be the exception. Game of the Year material, in all likelihood.
2) Shadow of the Colossus
The team behind Ico have a line of credit with me that lasts until they lay SEVERAL eggs in a row. I'll play anything they've put together solely on the strength of what they were able to accomplish with Ico. The media released on Shadow of the Colossus points to them doing a lot of things right and very little wrong. This and Zelda are the two I'm picking up on Day 1 of their availabilities.
3) Sly 3: Honor Among Thieves
The worst thing anyone has said about this game at E3 is how it isn't that much different from the first two; I loved the first two. No problem there. Count me in.
Strong Interest Titles, Possibly To Buy:
1) Prince of Persia 3
Loved the first one, enjoyed the second one with reservations (the ridiculous forced 'attitude' and infusion of Godsmack, all of the rumored glitches I feared after reading up on the game online before playing). If they can recapture some of the magic forfeited in the name of "grittiness" in part two, I'll sign on again.
2) We Love Katamari
I'll need to see if there are any evolutions to the gameplay; as is, it looks awfully similar to the first game, which I enjoyed last year but don't wish to play a clone of this year.
3) Destroy All Humans!
Looks like it could be fun, and the ads indicate a wry satirical wit in the writing. The gameplay is still somewhat of a mystery to me, though. Might be like War of the Monsters, which was great fun... for about three hours, and then just increasing tedium.
Titles To Keep An Eye On (may not be out this year)
1) Siren 2
I'm one of about eleven people who was completely swept up in the first Siren, and will absolutely rejoice if its sequel is finally announced for American release.
2) Hitman: Blood Money
Hitman 2 was astonishing, and kept me busy for a solid month as I worked for Silent Assassin rankings on every level. Hitman 3 was not as impressive, but I still carved out a game of all Silent Assassin rankings (and not a single bullet fired through the entire game... [pats self on back]). Assuming the fourth game retains even a respectable fraction of parts two and three, I'm helpless to resist.
3) The Suffering II: Ties That Bind
I enjoyed the first Suffering with reservations, and take a bit of a 'wait and see' attitude with this one. If it's received badly, I'll wait until it plummets in price and pick it up used on the cheap, or not at all.
4) Fatal Frame 3
No idea if this is even tenatively planned for this calendar year, but I've seen some media on it and await it eagerly, having loved scaring myself half to death with the first two.
That's all I've got. Needlessly thorough? Sure, but I'm listless and bored.