Something that it is NOT good to be, despite people seeming to think so. Basically, this generally refers to people forced into a harsh life due to their low socio-economic status, who probably feel forced by circumstances beyond their control to live a certain lifestyle and commit crimes to get by.
As far as I can say, any "real" gangsta would either be dead, or in jail serving a life sentence for murder. People like to praise gangstas, but what's praiseworthy about commiting murder?? I don't think that committing crimes is a prerequisite of gangstaness. If gangsta is to be used as a positive term, it should be used to describe people who successfully and legally make their way out of the ghetto and improve their status in life. We should pity those who live in dangerous areas and constantly have to watch their backs, but we should not praise them for committing crimes.
I think it's child, the way people define gangsta as somebody who has killed somebody or shot somebody. If you did that shit your ass would be in jail, especially if you bragged about it, and especially if you bragged about it on internationally popular records. You gotta wonder, if all the gangsta rappers are actual gangstas, how are they still free?? Famous people can't commit murders, brag about it to millions of people, and get away with it.
So having said that, I don't think a gangsta has to be a killa or whatever. And a wanksta is someone who trys to be a gangsta but ain't. But don't over-simplify. Just because you done a bid, or shot someone and got life, or whatever, it don't mean you gangsta.