If you are downloading the PS1 classic there are some pretty good ones for cheap,

FF7, FF9, Arc the Lad 2 and 3, Breath of Fire 4, the FF5, FF6 and Chrono Trigger rereleases, if you like tactics games imo Front Mission 3 is probably one of the best ever and definitly the best on PSX, Legend of Dragoon, Legend of Mana, Parasite Eve, Suikoden, Wild Arms 1 and 2, Xenogears

Personally I would stay away from Chrono Cross and FF8, I remember playing them back when they came out and they were good but recently I downloaded both and couldn't even get through them

If you are getting discs or roms somewhere there is a ton of other good ones too, Suikoden 2, Saga Frontier 1 and 2, Vandal Hearts, Lunar, Breath of Fire 3 and 5, and definitly a hundred more I forget,

In my mind the PSX was the best era for RPG's followed by SNES