IF there is a choice from gamefly, always get the game for PS3.
No other reason besides blu ray discs are more scratch-resistant.
Every 360 games I've bought so far had crazy chips and dents, to be fair though, everyone of them installed successfully.
If you don't get to play games as much as you used to, like myself, ALWAYS install them immediately to the 360 to verify they work.
You can always delete them afterwards.