A vigilante breaks the law when seeking justice often killing and/or maiming their opponent. Samartian goes and save the innocent even if it causes them problems and so I say Superheroes are Samaritans.

Both.

Some are samaritans. Some are vigilantes.

A lot are a combination of both, though the degree to which they are one element or the other varies.

I'd call them superheroes,I usually refer to more brutal crime fighting characters such as the Punisher as a vigilante.