So what is your guys favorite forum software?

If you ask me it's hard to choose now days because there are so many as I'm typing this post I can think of at least 10 that come to the top of my head.. I really like MyBB personally because it's user-friendly and you can add plugins and new features so easy.. I like Xenforo to but I just dont have the money to use it.. Maybe in the upcoming year I will.