...not really, there has of yet been a game on the PS3 that looks significantly better on the PS3. PS3's Oblivion only looks marginally better, so little of a difference most people probably wouldn't even notice. (the PS3 was only able to give slightly more draw distance) so you could see a bit further than the 360 version.

Face it the PS3 has some specs that are better than the 360, but they are bottlenecked by limitations elsewhere in the PS3 specs. In the end, the 360 and the PS3 are about the same. I can confidently say that the 360 will be able to handle any game that comes out on the PS3 with little difference.

Plus with exclusive episodic content for the 360 version of the game, I'd say the superior version will clearly be for the 360.

I mean if you only have a PS3 (I'm sorry) then it's version of GTAIV would be satisfactory of course, virtually identical game to the base game that both machines are getting, but if you have the option between the two and you are a GTA fan I can't see how anyone would rather have the PS3 version over the 360 version.