My favorite PS2 games that I own are Resident Evil 4 and Bully.
PS:
Final Fantasy VII & Crash Bandicoot 2: Cortex Strikes Back (or it is called "The Wrath of Cortex" I can't remember)
PS2:
Final Fantasy X & Final Fantasy XII
PSP:
Syphon Filter: Dark Mirror
Grand Theft Auto: Liberty City Stories
Daxter
PS3:
Rainbow 6 Vegas
Resistance: Fall of Man (before I got sick of it)
Ps2: Star Ocean: till the End of Time
Ps3: Tekken Dark Ressurection online(it will probably be MGS4 though)
The two Dark Cloud games (oh so tough, but oh so good), KH I and II, MGS 3, and GH I and II.
'Ss about it.
RE4 and Endgame. Soon it will be RE5 for ps3.
Star wars battlefront 2, GTA 3, Vice city and San andreas.
GH2/RT80s (GH1 was annoying, merely because of the impossible hammerons and pulloffs), KH1/2, Ratchet and Clank: Going Commando/Up Your Arsenal, GTA: San Andreas, and soon to be GH3.
That's about all I play anymore. :P
warhawk / resistance