The PS1 is kinda old for me since i was born in the early 90s, but i still played NES and the SNES over it.
But the PS1 was awesome since I have most of my Final Fantasies on it, the Resident Evil series, Chrono Trigger (Pfft i hate Chrono Cross) and I don't really remember what else I played on it. Nothing worth mentioning. Note that i didn't actually find MGS until the PS2 days.