Well, first of all it's been a great year for gaming, at least on the PS3 and I have had the luxury of completing all the visual show pieces including KZ2, UC2, Res5, ACII and Batman AA, only reason I don't mention MW2 is coz it's just not visually nextgen, I'll elaborate later.
I had a hard debate between KZ2 and UC2 but ultimately chosen the one and only, Killzone 2. But these two titles have brought the utter most shock and awe in terms of graphics and total impact, to me they're really a league above the rest. You may argue UC2 has a longer laundry list of effects but everything that's in KZ2 simply created the most CGI esque experience I've ever witnessed, the death animation, shadows and particles are the deciding factor for me. UC2 is just another kind of awesome but it's just not as convincing in a sense.
In regards to MW2, I think it's a good looking game with tons of actions on screen but everything are just second grade in comparison. The game seldom use any nextgen effects such as object motion blur, HDR, Deferred rendering, advanced mapping, physics, average animation and average res textures. 60fps is good and all but personally I'd rather take 720p 30fps any day for higher visual impact. I can understand some might like it for the presentation and fast action military cool factor but beyond that I just don't see a damn thing worth mentioning.
Finally, judging from what I've played of the GOW3 demo, I have to say the final game would seriously threaten the likes of UC2 and KZ2 graphically. I'll leave it at that
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