I have had shows that I've obsessed over. Now I tend to watch more independent/experimental films and foreign films. Music is my main obsession though, I almost always have something playing. It calms me and makes it easier for me to think. I obsess over playing guitar, I'll sit there and play the same riff/chord progression until I get it perfect.
I also love writing poetry and writing in general. I obsess over spelling and grammatical errors. Like for instance: it really bothers me that you spelled weird incorrectly. :p It's like nails on a chalkboard errors as such. I have poetry forums that I go on and I'm known as a grammar/spelling nerd.