Harry Potter: Like get me some Dramione any day. Amazing stuff
Supernatural: Pretty much all over Tumblr, like everywhere
Game of Thrones: It's got a little bit of everything, so I'm not so surprised that it's everywhere
Marvel: Yea, this is kinda general, but they all have pretty big fandoms
Phan: Dan and Phil!!!! Whoooo!
One Direction: I don't get it, well actually I do
Star Wars: YODA!
My Little Pony: BRONIES!
Twilight: 50 Shades of Gray came out of this fanfiction....
Percy Jackson: don't know much about it, but it's everywhere
Bleach: One of my favorite animesss
Dragon Ball Z: Goku screaming yes