Would you get an anime-related tattoo?

err.... Shiji-kun i think you meant Mustang's gloves or Armstrong, Edward doesn't even need one. The other thing you could be referring to is the symbol for the alchemist title: Fullmetal Alchemist.

Anyways, i would like to get one but i'm too much of a wuss. But the best ones i can think of are:

command seals (fate series), specifically Emiya (any of them), Rin,or even Kiritsugu 8 command seals on his arm (fate zero) or the magic seal or watever symbols like that fish looking one in unlimited bladeworks.

transmutation circle, mustang's one or even Scar's one (fullmetal alchemist/brotherhood)
[/list][/list]the homunculus symbol

maybe Naruto's seal? (probably too weird)

Maybe even fake sharigan eyes like Danzo (again probably cool but weird)
[/list][/list]or any of Sal's ink art

or even LoL characters

Well, the ONLY thing I would actually go for (If tatoo, means permanent, not the Henna type, because I would do ANYTHING if it wasn't permanent :P) would have to be "acceptable" by the general society, not be flashy, and be humorous for those who can read the message. I would go for a dark-red ink, 5-cm diameter, "Homunculus" symbol by FMA, on the highest part of the back, right under the t-shirt neck line. This tests any serious relationships I might have on their knowledge. They asked "Honey, what is that?", I reply "You don't know me enough!"

That would be awesome, the only thing about red ink is that it's next to impossible to remove.

or Mugen's blue tattoo marks on his wrists and ankles

I'd love it on my left peck :o
Get it somewhere you can hide it with clothing? :o
Else, just wear gloves all the time, so nobody can see it ;D