Mawile is actually used a lot. It also has a mega evolution and a very high attack I think.
Definitely my Rhyperior. I searched for a shiny one in the Friend Safari for five days and as soon as I told one of my friends he said "wow, Rhyperior sucks." :'( I'm sure it'll be useful though, especially with Talonflame and Aegislash so common this gen. :)
I use Dusknoir right now.
If it's a ghost pokemon people use Aegislash, I caught two players with Aegislash off guard today with Pain Split and Earthquake.