I actually have played only FFL2 and FFL3. I agree, those games are pretty good for their old age.
But they're actually, very challenging to finish!
Final Fantasy Legends II is crazy hard to beat. I mean If you don't know what you doin, then Kiss the Game Ending Goodbye, cause You'll never get the chance to see it.
The Training system is very random in that game.
Also the Final Boss for FFL3 was longest/hardest Boss that I've spent time on, to actually take out. Took me about a Month to get lucky enough to Kill em.
Overall, I give them both 7/10 The Story IS pretty decent...