If you had asked me back before Batista got hurt, I'd have said Dave in a heart beat. The guy was just naturally charismatic, whereas Cena was "Johnny Forcedthroat". Now, I think Cena is the less irritating of the two, and a lot of that has to do with his future and the skill he does have, even if it never shows up in his matches.
I would rather take KoOS' suggestion of a battery acid bath, though.