Born This Way closely followed by Firework. I don't actually like either but they've both become global anthems for the misunderstood. Anyone who says otherwise is lying to themselves.
I mean that song is going to be played every year from now on around Fourth of July and pretty much anytime there is a massive celebration of anything.
Firework, easily, with Born This Way following very closely behind. Only song I even kind of like on this list is TTWE, but Firework is one of those songs that will be around for ****ing ever.