at the risk of sounding like a fanboy, the 360 ones look slightly more polisehd than PS3 ones

That's seemingly a bit of a trend at the minute.

How can you tell which is which ?
And tbh the ps3 is just a bitch to code for, also there is a rumor that gta4 on the ps3 isn't even real HD its just upscaled.
So I would be pretty interested to see some high res screen shots of those two games compared. Not some shitty low bitrate video on gametrailers mind as that doesn't prove jack.

I think the ps3 lacks the AA of the 360, at least I notice more jaggies in most games anyway.

However the ps3 can still make a game like mgs4, which blows away any game on the 360 in terms of gfx and textures etc.

Guess it all comes down to time and effort in the coding.

Actually I think its that the ps3 version is using filters, like grain filters to enhance the atmosphere, this is a common trend and not one I like.
All it serves to do is annoy me and detract from the graphics.