A couple of other suggestions for the PS1/PS2 beyond the usual ones:
Shadow Hearts and
Shadow Hearts: Covenant
Great scripts with great characters and even a few historical personages. The games are set just before and just after the onset of World War I, but the world they inhabit includes a few additional items like monsters, demons, and warlocks. It also employs a somewhat non-standard battle system, though it's turn-based like most JRPGs. The third game in the series,
Shadow Hearts: From the New World, is a pale imitation of the first two, especially because it lacks those games' male protagonist, Yuri Hyuga, one of the best game characters ever written.
Wikipedia page; warning, there be spoilers here, matey!
ChronoCross
Perhaps the best RPG for the Playstation 1 despite what the Final Fantasy fans might want to say about those games. A wide array of characters (perhaps too many actually), beautifully drawn worlds, and a spectacular score by Mitsuda make this one of my favorite games. It's one I've replayed at least three times now. Some people criticized the game for not being sufficiently faithful to its predecessor,
ChronoTrigger, but I played the games in reverse order, and it mattered not a whit.
Wikipedia