I just finished Path of Radiance and kind of wanted to talk about the series.
Mine would probably be Blazing Blade or Mystery of the Emblem, BB because having some weird cult terrorist group as the villains was more fun than Evil Nation nº12837, MotE because i think it has some of the best gameplay and maps of the franchise while having a way better story than the other newer FE games (that i have played, Awakening and Fates).
Genealogy of the Holy War! It's a little tricky to understand compared to newer FE, but it great and should be mandatory for any SNES JRPG fan.
It's also the origin of the matchmaker stuff from Awakening. Only it makes more sense since the second half of the game has you playing with all the children as your units.