Hm...Crysis pushed pc graphics into an entirely different arena. GTA IV looks great, no doubt, but Crysis was *made* for shooting and blowing crap up; the particle fx and explosions in Crysis are superior. And the alien ship level? Come on. The environments in Crysis are spectacular; GTA is a city..which looks great, but a concrete jungle...and a real jungle. I didn't find myself stopping and saying, "Wow, that looked great!" in GTA because GTA is about the gameplay. Crysis had me just walking around and looking at things (yes, I understand that GTA you walk or drive around and look at things, but the details were hardly at the forefront of my mind when I'm chasing someone down to shoot them).
I'll save your time by simply saying Crysis over GTA IV (I think it ported to PC poorly anyhow) and link you some "evidence":
Maxed out GTA: [ame]http://www.youtube.com/watch?v=ySIX71tXsVo[/ame]
A maxed Crysis: [ame]http://www.youtube.com/watch?v=IzxjWCx6Bs0[/ame]
Sad to see Gta 4 has got more votes than Crysis -_- The thing is, crysis requires one hell of a system EVEN TODAY to run it at the max settings(with the mods applied)