The original Spyro games (the 3 released on the ps1) were masterpieces, all of the rest were.. how should I put it... ****!
I've never played Driv3r; the general consensus is that it sucks, but I still occasionally play Driver 2 (PSP ftw).
I'm surprised nobody has stated JO. Dark Forces and Jedi Knight (yes, even MotS) were fantastic, but I sensed a degradation of quality in JO.
Splinter Cell in my opinion had amazing potential, but there were definate bad points that sort of ruined the game for me. The lighting isn't very consistent, and although the sneaking action was many times greater than MGS, Metal Gear has an infinite times greater replay value, and even during the first play through Splinter Cell felt repetitive (switch, guard, camera, guard, door, repeat).
Metal Gear Solid: Portable Ops failed miserably, and in my opinion it was for the simple fact that the PSP lacks two analog nubs. That lack, in fact, was the primary cause for the PSP's failure. Since a huge majority of PSP titles are PS2 ports, the control schemes are always jacked around with, and the games never feel quite right. Also, only one analog nub effectively eliminates the FPS genre from the PSP. Portable Ops was good for a PSP title, but for the average system? FAIL.