Oh all three you haven't watched are the ones that are not much popular these days, especially because of their art
style and themes
Vagabond is based on Yoshioka Eiji's novel, written by same mangaka who made Slam Dunk, it's based on a Samurai and his
spiritual journey while he walks the way of sword. (has some mature scenes in one or two chapters)
Slam Dunk: One of the best shonen manga i've read, very fast paced and interesting with a disappointingly abrupt ending,
but that makes it short and easier to read (unlike manga like Hajime no Ippo (1000+ chapters) and one piece (700+)
chapters which are too daunting for some to start reading)
Hajime no ippo: again, one of the best shonen manga I've read, it's long, and some arcs are boring, but it's a very
motivating manga for sure. And i think it's the most 'shonen' manga I've read till date. But it also has many scenes
many many references to male genitalia meant for humor, so not recommended for
girls ^^;
My favorite characters from FMA manga are ofc Ed and Al, but also Pride(that badass guy with eyepatch, dunno what he's
called in anime) and Greed (the homunculus that possesses the oriental prince)