Rottweiler, because they are a great attack dog to take into battle, (incredibly stong jaws and body power) One of the smartest Breeds, (even if mine acts like a [censored] 90% of the time) Gentle giants when they wish to be, They will defend you to the death, and they look great in the snow!
I have a project going at the moment I'm making a fantasy world and I have 3 dog races, One is the Gnolls (Wolfmen) and then there's The Rottica (need I say explain) The Gnolls are clans of barbaric packs who are fairly primitive. And the Rottica are an Honorable Warrior Race who never ambush or attack from behind. They live in a City under the Dollag Mountains and are know for the high Quality Steel Armor and weaponry matching the steel work of even Dwarves but not the crafting of other more precious and prestigious metals. There are also a small Tribe of cross breeds hidden in the peaks of the Dollag mountains But the cross breading of the 2 was made impossible by a curse by St. Bensith after he was ambushed by them. He Said "Their Lack of Morals And Their Intelligence Makes Them A very Dangerous Race."
By Azura! I Don't Half Get Carried Away, I'll stop now
But Yeah the only thing the Fable series had going for it was the Doggy companions.
Also the wolf type dogs Husky/Malamutes would be cool and fit Skyrim Perfectly