solo games
FFX and FXII (FFIV V VI VII VIII IX are avaible on PSX too)
god of war I and II
RE4 (u can also try others RE games)
silent hill (try the 2), also try SH1 if u can
MGS 1 / 2 3
casltelvania : symphony of night (PSX)
Final fantasy tactics (PSX)
Vagrant story (PSX)
GTA (if u like)
if u want multiplayer games :
PES
FIFA
GT4
Soul calibur 3
Tekken 5
Time to Work !