OOOOOOHMIGOSH. Yes, watch it @_@ It is one of THE best anime in existance O_O *dead serious *
I could ramble on about it, and all three of the versions... but everyone already did that ^_^
The first anime: The most touching of the three, with a little more weighty involvment. It's very sweet, and has GREAT quality (soundtrack, animation, actors, everything) The main character, in my opinion, is best here.
I LOVED Ed, he was my favorite <3 Mustang was such a close tie though O_O
Manga: It has a much, much grander plotline than the first anime. Goes to hugely epic proportions, sometimes almost overly so (the climatic scene... eesh) But it's extraordinarily involving, and I ended up crying more times in it than I did in the anime. >_> <_< The once I did cry in the anime was much harder, though... hmm... *crying is not connected to actual moods though, so this may not be accurate * Anyway, more charas with more plot involvement. WOOT! Even little side dudes get their time to shine
I liked even more characters here than I had in the anime, but ultimately, Ed dropped a lot of notches, and everyone else climbed higher.
In the manga, I am torn between Prince Lin and Mustang
(And after them, Hawkeye and Envy)
Brotherhood: Umm... same plot as the manga, of course. But the animation is cheap (which, in some ways, makes it look awesomer XD ). The soundtrack sometimes doesn't really fit... But it's growing on me. The new English actors aren't so good, but most of the old actors come back to act again
The first few episodes just skim what they already animated through the first... so... it's not all that good at first, but they added enough new material to keep it awesomely interesting
Alright... done stating what others have already said... *skuttles off *
XD