I've only played a bit of Uncharted 2, and only seen a couple of vidoes and screenshots of Alan Wake, but from what I've seen I enjoy the setting and lighting better in Alan Wake.
I have a slight problem with the texturing in Uncharted, textures look really bad when you get up close, and quite cluttered when viewed from afar, and they are way to saturated for my taste. This takes away all of the truly breathtaking quality of the graphics. I'm also bothered by the character design. The style they went for is not very realistic, and the setting of the game reminds me so much of a hollywood movie that the un-realism stings my eyes a bit.
The Alan Wake movies and screenshots gives off an atmosphere closer to Film Noir and thrillers than an action movie, and the lighting and texturing fits very well with that. There are also some very, very beautiful screenshots out there. There's something wrong about the graphics though that I haven't yet been able to put my finger on though. Maybe I'll know more when I play it.
For now, I enjoy Alan Wake a bit more.
(Shadow of the Colossus is still the graphics king)
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