Allow me to chime in with my obligatory comment about how I never thought much of any of the Mana games anyway. Secret of Mana was pretty good, but still manages to fall pretty low on my favorite SNES RPGs.
While Secret hasn't aged as well as other classic SuperNES era RPGs, it still 'is' a classic SuperNES era RPG. It's basically that stepping stone between FFs IV and V plus games like DQV, and FFVI plus games like Chrono Trigger and DQVI. Also, despite the issues that plagued it's implementation, its probably got one of the best implemented FF2 style 'use to level' systems this side of the PS2 era (though it still had issues thanks to dumb crap like the Girl and Sprite's weapon levels rising half as fast as the Boy's despite the fact that they also had to focus on raising their spell levels), and the multiplayer aspect wouldn't see a match till the PS2/GameCube era (at least in terms of having an FF style JRPG with actual multiplayer interaction).
And while I'm here:
FFA was actually very good for its time considering that it even predated the game that Link's Awakening was built off of, For Whom the Frog Bell Tolls. That said, its plot is totally an 80s anime and a lot of its assets came from the FF games before it.
SD3 was probably the last good game in the series, but its also the one that every game since has borrowed the most from (while pretty much ignoring SDs 1 & 2). It's also less of an upgrade from Secret and more of a sidegrade by switching out the FF2 'use to level' system for classes and three marginally alternate campaigns and not doing much else.
Legend was an amazing, half broken, piece of crap. Unfortunately, in spite of it's amazingness, the game's still ultimately a half broken piece of crap. Its also where everything that wasn't derived from SD3 was derived from. It's also a product of the Summer of Square (which also gave us Chrono Cross and Threads of Fate) which wasn't too bad since the game quality was overall good when taken on the whole, but it was also the start of Square's (later Squeenix's) love affair with compilations.
Sword somehow managed to take in parts of the entire series up to its release (including remaking the first game), and still coming up with something that felt incredibly shallow and half-assed. It says a lot when you have the plot of a GameBoy game fly almost completely off the rails due to over-characterization and simply saying more than they actually had to say.
Then the entire World of Mana compilation was complete garbage. Full Stop.
And then there was Dawn (which while technically also part of the World compilation, was also its own entity and what the World compilation was building up too) which was a janky action platformer that made Kingdom Hearts 1 look good by comparison. It was also a game that was almost entirely about designers at Squeenix running around and shouting "Look at us! We're using the Havok Physics engine like all the westerners use.".
There's also Circle and Rise, the former being yet another Japan only CCG, and the latter is something I have yet to hear the verdict on.