everything was wrapped up perfectly. everything made sense. nothing felt out of place or unnecessary. very memorable.
even the dub was amazing,
moreover the female characters aren't treated like crap by the author (ahem like in Naruto) which probably has something to do with the mangaka being a woman. Unlike in other stories in battle shounen Fullmetal alchemist portrayed a romance between a man and a woman that didn't involve the woman also fighting, but in an equally useful role (mechanic) because other battle shounen (ahem naruto and bleach) just sideline them and make them useless in fighting anyway lol
the story dealt with some nice philosophical issues without going into territory the mangaka wasn't equipped to handle efficiently and with nuance (ahem attack on titan).
The idea of "alchemy" as a power system was also very unique and memorable.
