I think Killzone 2 looks pretty good. I personally can't comment on Crysis as I've never really seen it at full capacity.
Wouldn't it be entertaining if a game that came out in the first few months of 2009 swept all the 2009 GOTY graphics awards?
People are already up in arms about MGS4 winning multiple graphics awards (over Crysis I might add), I can't wait to see what happens if Killzone does.
It's also going to be fun when reviews start coming out and we'll have reviewers saying this is the best looking game on any system to date (always happens with games that have hyped up graphical prowess), just to see people flip out all across the internet and write a novel about how much better Crysis is.
In the end, it doesn't really matter, they both look great.