I'm going to have to go with Buizel. As of now, I don't think personally, that we've seen enough of Tepig. I would like it to gain a little more personality as it evolves, because as of now I find it a little boring.
I didn't just choose Buizel because I'm not too fond of Tepig yet. Buziel has proved itself to be a very powerful battler, and even though some of us would have loved it to evolve, I think it's pretty awesome either way, with a very cool personality at that too.
But yeah, my vote goes to Buizel.