I'm a fandom tourist - I mosey through and take a few pics, but I don't usually stay for long before moving on to something else.
I suppose the few that have made an impression enough for me to buy merchandise are Star Trek, Buffy the Vampire Slayer, and Firefly...also various gaming-related things like D&D t-shirts
I know this isn't quite what you asked but I follow the NFL and NBA quite a bit.
Mmmm it still being a fan of something
Game of Thrones has all kinds of awesomeness on YouTube. I've Patreoned some of it, just because it is so soothing to fall asleep to.
I named one of my cats Kaleesi
Hunger Games - Books and movies. Am reading all of the Harry Potter books now and will watch the movies when I’m done.
Star wars and trek, some marvel and dc not a super, big marvel or dc fan
Too many to mention. But I have to say that I can't wait till season 8 of Game of Thrones comes out.