Is graffiti a legit art form? I think it is. I love it. That's why I used it for my new background. There's probably a bunch of old timers that think it's all heinous and inappropriate and criminal. It can be, but only, in my opinion, if it spreads messages of hate or violates other art. If it's done in a creative manner and doesn't break one of my rules then, thumbs up! It's another form of freedom, freedom of expression.
I'm a big fan of graphic art, so that's probably what I'll talk about here for the most of the time. This includes vintage posters, comic books, advertising and street art. I think that's what they are calling graffiti now. My favorite source for street art is Street Art Utopia. Check out their website (link below). It's a site where people submit the street art they see around the world. Skim through it. You may be in awe of the creativity of the human race and maybe inspired to do some of your own.
Street Art Utopia