Eight Divines. Talos is a false god and has no right to be worshipped as one... but that's my opinion as I am a staunch supporter of the Altmer and the Thalmor.
I believe the Daedra would win, mostly because I love them more than the Divines. I mean, what have the Divines given me? Even Peryite, the weakest Prince (or one of), gives me an awesome shield. I don't know, I just don't see how Zenithar is going to be helping out his team by giving them better prices.
Zenithar: "Hey Stendaar, wanna buy a new sword? Special price, 40 septims!"
Stendaar: "...Aren't we on the same team?"
I'm not saying it would be easy though. I mean, Akatosh is pretty badass, and it's not like all the Daedra are suddenly going to become best friends and fight as one. But if Akatosh went down, the rest of the Divines would fall as well.
I suppose Sheogorath could take back my Wabbajack and turn Akatosh into a sweet roll...