I got kind of sick of fanfiction. I kind of hate the fact how people do absolutely crazy things to characters that I'm sure they would not appreciate.
I mean - would Sasuke normally run around in a tiara and tutu? *sobs* Those poor TV characters! Their lives are being run by crazed teenage writers!
So yeah, I prefer to write original stories, but when I get writer's block time (which is absolutely evil), I ease it with a bit of one-shot fanfictions to get me in the mood. But I always make sure they're logical and fit well with the actual storyline.