it's easy, they are numbered :p
personally, I did
Adventure (technically secret of mana series)
Legend 1 (technically SaGa series)
Legend 2 (technically SaGa series)
Legend 3 (technically SaGa series)
IV
VI
Mistic Quest (remake of I forgot... you can skip that one)
VII
VIII
V (Fansub rom FTW)
IX
X
XII
XIII
gonna play the 1-2-3 in DS version when I have the time ^^
OoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoO