I'm going to kick my roommate out in january
Does he owe back rent?
No, but I hate his face and I want it to go away.
What makes you think the next roommate will be any better? People can always get on your nerves, but that's no reason to kick them out.
Kicking people out is my hobby. I really don't care if they have a place to live or not
If your roommate has done nothing wrong, then you could be breaking the law by kicking him out so suddenly, so it is not worth the risk.  Furthermore, word travels quickly in the rental community, and if people learn that you are a bad roommate yourself, they will not want to live with you, and this could make it difficult for you to afford the full rent yourself.