Out of those two, I'd have to go with Legend of Dragoon. I recently played through it again on the PS3 and the graphics hold up remarkably well with the smoothing feature on(considering it's PS1.) Curious to see how they'd approach a remake on that, apart from making a 4 disc game into one. Full 3D? I really liked the battle system in that one. I'd prefer a sequel, though.
I'd also agree with everyone who said FF6 and would add Phantasy Star 1.