This thread pretty much proves why the PS1 is one of my all time favorite systems. It had so many really great JRPGs.
Anyway, of the ones you have, I have played Legaia and FFT, though I want to play Lunar 2 at some point.
FFT is a game heavy on strategy, which rewards players with a little patience. The story can be confusing, but really damn good. It's certainly among my all time favorite games and I have beaten it several times over.
Legend of Legaia uses what is probably the best combat system in JRPGs. No options are useless, attacks are unique, and the magic system is pretty good. I'd say that the story is pretty standard for JRPGs, though. In the long run I do still consider it among my favorite JRPGs, though, which is saying a lot.
I'd probably play Lunar 2, since I haven't played it.
Elvis Starburst said:
I hope you don't mind me making an extra suggestion, but I can't recommend Suikoden 2 enough. The first was... ish. the second was beautiful and fun, and it's probably my fave RPG. It's amazing I only just experienced it last year. It's on the Vita PSN, and maybe the PS3/PS4, I'm not quite sure on that. As for your actual choices... Tactics, I guess?
And I just want to affirm how good Suikoden 2 is. It's seriously among my Top 10 Games of all time. It's that damn good. Though, playing the first wouldn't hurt as several characters return, the story takes place in the same general region, and loading data from the first gets you bonuses, like being able to get the hero from the first game as a member of your battle party.