Which one do you use the most? Let it be from the game, a DLC, a mod...

I'll give you a clue about mine: it's a shouting bear.

Ulfric Eh? I'm still discovering followers as I go. Mjoll is atm but Serana will take that spot until/unless I find another I like adventuring with more.

Wrong. http://skyrim.nexusmods.com/mods/30638.

Then again, I said it: any follower, let it be vanilla, DLC, mods...

If I had no mods? Marcurio. When I still played vanilla he was the one I stuck to the most. And he's still one of my favorites. I've never had a character who didn't use him.

With the mod for it, Ulfric. He enjoys it so much I just hate to leave him at home. Plus it's fun to watch the roadside thief who foolishly decided not to walk away go flying away instead. Watching him disarm Draugr Deathlords and send them running for their un-lives is also very amusing.

Since I'm on 360 it explains my ignorance. Looks fun though.