I loved the PS1 era. Aside from a select few Nintendo games Sony had everything.
My personal favourites are (in no order)
1. Tomb raider 1, 2, 3 (4 and 5 just got a bit dry, exactly like the Assassin's Creed series!)
2. Resident Evil 2
3. Silent Hill
4. Final Fantasy VII, VIII, IX
5. Metal Gear Solid
6. Gran Turismo
7. GTA
8. Future Cop LAPD
9, Crash Bandicoot 1 and 3 (never got round to buying 2!)
10. Destruction Derby 2
11. Tenchu
12. Tony Hawk's 2
13. Micro Machines V3
I still to this day think beat-em-up games are all the same and suck - Yes Tekken I am looking at you! You can finish them in 10 minutes!
My brother had a Nintendo 64 and I loved Pod Racer, Goldeneye and Ocarina of Time, but these few games did not even come close to the awesomeness of the PS1. The PS3 is living in the shadow of the PS1 and PS2 imo.