Me I'd be Sithis, purely because he is everything, but mainly, the Void. Also because he is so mysterious.
Don't you mean "FU Thalmor"? By most accounts, the only reason that the Empire supresses it is because they were forced to. And even then, it's just "let's say this to make the Thalmor happy until we can kick their heads in."
Akatosh. Whereas all the other Aedra and Daedra have limits to their knowledge, as the god of time, I would know all. Also, I'd be a dragon.
Meridia, "… thus does Merid-Nunda [ride? slide?] across the rainbow road from end to end, at one end stretching the dragon, at the other end compressing him ….". That's some big gris-gris in her bag.