Chrono Trigger (though very well known) is an excellent one that had its art drawn by none other than Akira Toriyama. Complex story which can suck you in for quite a long time so I'd recommend setting aside a lot of time for yourself to play it, though the same applies to my next recommendations.
Legend of Dragoon is another one that came very late into the PSX's lifespan (2000) and had subpar graphics compared to earlier titles, however the combat is innovative for the time period and the story is quite good. Though the grinding is a bit rougher than something like FFVII.
The Legend of Heroes: Trails in the Sky 1 & 2 have been suggested already, but I want to recommend them as well. Both games are very underrated and are my top 2 JRPGs I've ever played. The music as well as the characters are wonderful, and the worldbuilding is unmatched for the era imo.
Ys VI is a ps2 game developed by the same studio responsible for The Legend of Heroes series, and the same compliments for those two can be applied here as well.