This movie was the one movie that I could think (and find on iMDB) that I hadn't seen by James Gunn and after watching "Guardians of the Galaxy" and realizing that I knew it was time to watch "Super". While I tend to only watch movies that are either a) comic book related or b) documentaries I found this to be close enough to the comic book genre for me and, well, I had to watch that one James Gunn movie I hadn't seen as well.
In this movie, Rainn WIlson (who is most excellent on "Backstrom" currently) plays someone who loses his wife to a really crummy guy who wants her mainly just to do drugs. Coupled with other events, putting on a mask seems to become the only reasonable answer and, well, they even question in the movie why no one has done it before but isn't there a comic book called "Kick-Ass" and wouldn't that be in their fictional comic book shop? (I'm kind of surprised Kick-Ass wasn't name when the question of superheroes without powers came up, but not that surprised since this does borrow from that a bit)
I'm not really into watching movies a lot, let alone multiple times, so with "Super" I do feel as if seeing it once was enough. I also feel that it was solidly structured from start to finish. One shining example of that being the death of Ellen Page's character because, really, what else would she have had to do at the end?
Even if you don't want to be a James Gunn completist and just happen to enjoy comic book type of movies then this should have enough violence and humor for you to give it at least one run through. I know that it did for me, but I also just assume most everyone else who would care has seen it by now.