That Castlevania is like no other and even if you despise Castlevania normally it is still worth playing
Maybe it is time to move outside of PSX and move towards other systems, like Sega or Nintendo consoles, Sega do have some nice gems to offer (Megadrive to Dreamcast), Nintendo ones most have played through though, Translated ones for SNES are well worth looking at specially if there has been new ones done since you looked last, GBA though has tons of great RPG's both turn based and action (both with RPG stats so not counting Zelda ish games)
Beyond the Beyond is a very good game though for the PSX very much classic turn based style RPG, if you played the Shining Force games before (Megadrive to Saturn) then the battle system should feel familiar though Beyond the Beyond in not a strategy battle game RPG like Shining Force is, it's a single party battle system, the entire game even though it's more pure RPG than the cross breaded Shining Force, it does still have a Shining Force feel to it, hard to explain but I'm sure if you have yet to play it you will love it.
Xenogears, is also a great one but I'm going to guess you have already played that one
P.S. Grandia II is my fav of that series of games there are also at least 2 others III and Extreme that are all for the PS2 though (Grandia II is originally a Dreamcast game (best version with reportedly the highest quality FMV scenes) and is also on PC) [PC and PS2 versions use re-sampled FMV with quality loss, not that noticeable though unless you are comparing it]
Cyberxion 
Originally Posted by Zaladane
No one had mentioned Chrono Cross yet
