I played a bunch of Seiken Densetsu 3 translated on a ROM, but never beat it.
I played a tiny bit of Legend of Mana, but not enough to actually count.
I played Sword of Mana to death. I know some people didn't like it but I thought it was a great updated version of the original on GB.
Children of Mana on DS was ok. Definitely a different direction with its random dungeons and sort of non-adventure but the multiplayer was fun. Magic sucked in the game though.
Dawn of Mana was a big disappointment for me because of the whole "you have to start with 0 power ups each level" thing. And all the bouncy-things-around thing got old fast too, so I only played a couple stages of that.
Kind of disappointing the the SNES ones were the peak of the series... I don't understand why they never want back to that formula, since it clearly was the best.