I don't want ISOs. Piracy on my (dead) 360 has made me value the games a lot less. I've got over 40 pirated 360 games and most have had little to no playtime, some get played endlessly and I end up buying a legit copy in those cases (Forza 2, Blue Dragon for example).
If I started pirating PS3 games then that would be it for the system. I'll stick with pre-owned or rentals if I'm not sure the game's worth getting.