Full Compatibility List
If you're into 'going commando' you might as well just take your cyanide pill now and get it over with, but if you're an aspiring god of war then you may end up sitting on that throne in upscaled 1080p glory (pending the firmware supports it).
GRAND THEFT AUTO: SAN ANDREAS may be having a few problems, the compatibility chart says it will play with noticeable issues (most likely framerate and artificat problems). The Gran Turismo series should work with a few minor issues too.
In terms of RPG's you're out of luck, Final Fantasy's 10 and X-2 will both run with lots of apparent issues, 12 and Grandia will play with minor issues. Only the SCES-50971 Kingdom Hearts will run with no issues werein the other versions run with lots of apparent issues.
Devil May Cry 1 and 3 will work just fine but 2 may have some issues, God of War 1 and 2 will run with no known issues (yay). Resident Evil 4 SLES-53756 will run with a few issues and the other versions will run with with lots of noticeable issues.
In the world of Ratchet and Clank as well as Jak and Daxter you are completely out of luck, no titles from either of the franchises are compatible at all.
Still, espionage types should breathe a sigh of relief, Metal Gear Solid is fully compatible... that is if you have the Subsistence version, only the SLES-82032 of 'Snake Eater' is fully compatible and the other versions will run with noticeable issues.
If you're into pulling guitar strings you might want to consider quitting, nope, Guitar Hero isn't compatible either.