Harry Potter.

Yesterday, I was lying on my bed, just listening to 'Goin' back to Hogwarts' (by team starkid) and singing along loudly (way off tune). I realised that I was happier than I've been in a while. I had this huge and ridiculous smile on my face, and I knew for sure that there wasn't going to be a day in my life where I won't love Harry Potter. I don't know where my life would be without Harry Potter.

It's not just the series itself, it's the fandom as well. I love everything there is to love about it. It's truly amazing. I would give anything to go to leakycon this summer.
http://justanotherharrypotterdork.blogspot.com/2011/04/can-i-have-moment-of-your-time-to-talk.html