Dogs by far.
I was actually surprised by the "dogs smell worse" posts. Everyone I've ever know with a cat has the stinkiest homes (they can't tell though). Dogs don't smell bad if they're bathed at the appropriate times (like any creature). Cats aren't too bad if the litter is taken out religiously, but they still smell even when that is the case.
Anyways, one of my dogs protects me, keeps me warm, is always at my side no matter what. Probably the most dependable creature I've ever had in my life.
My other dog gives and takes affection, depends on me, cheers me up, worries about me, and helps me meet women.
I've had cats that would sorta do those things, but unintentionally. Like cheer me up; it was never because the cat wanted too, but because I associated my feelings with the cat in that manner. And I've never had a cat that was truely happy and excited to see me after get home from work. They could care less unless you got their food in your hand^^ They are cute and fun to watch though.