SNES has some legendary RPGs, Chrono Trigger is one of the best ever.
But FFVII, love it or hate it, really blew the doors open for RPGs in America. After that, we got a TON of RPGs, especially JRPGs, and especially on the PS1. Between Squaresoft and Working Design's releases alone, the PS1 takes it. Not only the JRPGs, but thanks to the popularity of Diablo, we started seeing action-RPGs proliferate more, as well. And out of the consoles, PS1 got the best selection of those, as well (though nowhere near the PC, still).
There were so many different RPGs, too, between sub-genre-stretching titles like Diablo, Parasite Eve, King's Field, Legend of Legaia, FF Tactics, and Brave Fencer Musashi; and we STILL had the old stalwarts like Dragon Warrior, Breath of Fire, and Final Fantasy. And we even got some arguably superior ports of last-gen titles like Lunar Silver Story and Eternal Blue, Final Fantasy V & VI, Final Fantasy Origins, and Chrono Trigger.
PS1 wins.