The only bad thing about the newly released ICEnhancer 2.0 for GTA IV is the sense of sadness that a setting as beautiful as its recreation of New York will never be used again. Imagine the stories these streets could still have to tell, if not for our constant thirst for new worlds to conquer. Sigh. Anyway. As much as GTA IV was a system killer at release, you'll need a system-killer-killer system to run this as nature intended - but it'll give you one of the most beautiful games on PC if you can. If not, at least you can enjoy the vicarious thrills of this video. A new version is out soon that tones down some of the extra shiny in favour of a slightly more realistic look.
(Ignore the occasional flickers. Apparently these are issues with GTA IV's built-in recording tool.)
Still unimpressed? Check out the beauty of earlier versions at Dead End Thrills