Get Vandal Hearts. Best game I played on the PSX. Its a turn based Isometric RPG. I still load it up to play quite regularly on my PC (havent had a PSX for 3 years now)
Other Games definately worth having..
Parappa the Rappa. Great party game
erm.. thats all I can think of atm. Ive got five games at home
which I kept even though I sold the PSX.