Dino Crisis in this list is the only I played, but it was a great game from what I remember..
Some must plays I loved were Medievil, Tekken 2, Tony Hawks Pro Skater 2 is always great on the PS1, Oddworld Abe's Oddysee was so brutal as a kid but a great game as well. Other worthy mentions are the Die Hard Trilogy, the original Destruction Derby and Metal Gear Solid.
So many awesome games though for you to enjoy playing mate. We have my partner's chipped PS1 and cracked games but I need the square non chipping physical hardware and games, Final Fantasy is also on the list of a must for me to get!
I had so much fun with Tony Hawk back in the day, smashing sound track.
I had Die Hard Trilogy on disc, and of course Metal Gear Solid. MGS2 (though that was PS2) was one of my all time favourite games.
No spoilers, but it feels like that game predicted the current future we live in very well, lol.