I think MGS4 is one of the best games ever made, it is as epic as it is beautiful to look at. MGS4 boasts of really high quality visuals but it looks like there is a new contender for the crown, none other than KZ2. Fans at the PS3extreme had this to say:

While Konami’s Metal Gear Solid 4: Guns of the Patriots put up a decent fight, it was Guerilla’s Killzone 2 that ended up winning the battle: according to PSXE readers, it’s the most visually impressive title of the generation thus far.

There’s no denying that KZ2’s graphics are absolutely astounding, and even though it’s difficult to compare them to MGS4’s, one can’t deny Guerilla’s stunning achievement. It was about the little details that you don’t normally see fused with an atmospheric intensity that is unrivaled. It has most definitely set the bar for future FPSs and that’s exactly what one should expect from a “measuring stick” title; it should set an immensely positive precedent.

Source.