Impossible to tell... So many good games..
Here's some of them
Silent Hill - The story is so good. The music can be weird sometimes, and wonderful sometimes.. A really great game!
Metal Gear Solid - Whoaa, Snake. Again! Nothing better than running around with Socom killing soldiers.
Final Fantasy - FF games are great! Even though like "50" hours sounds alot.. it isn't that much. Since you get into the game just as it starts.
Dead Or Alive - Lost of people complain about the girls HUGE breasts..
I just ignore the breasts and everyone that complains and enjoy the best fighting game ever, DOA. (Brad Wong rocks!
)
Xenogears - This game is awesome this far (never had time to finish it since the guy took back his PSone :|)
The music is just lovely.
I hope that I'll be able to finish it someday!
Zone Of The Enders - Want to be cool for a moment? Want to fly around killing enemy after enemy in just a while? Want to get your hands on a mech? Great! This game is perfect if this is what you want. The 2nd Runner/ANUBIS is really awesome! (Go Jehuty ver. 2!)
I didn't add any numbers to the games since some of the comments was about all of it and not a single game..