Depends how you look at it and what kind of werewolves/vampires we're talking about here. I'll go with werewolves almost any day, but you have to be a bit more specific. Are we talking local folklore vampires vs. werewolves? Bram Stoker vampires? Underworld vampires and lycans? Video/pc/pen and paper creatures?
Either way, i'll go with werewolves as said earlier. However, in some versions there are differences. For example, initial folklore spoke of werewolves as those that had been bitten by wolfwere (imagine werewolves but the other way around, meaning their normal form is wolf and abnormal one is humans). These initial werewolves had no way of keeping themselves from turning or controlling their turnings when the full moon was up.
HOWEVER in some games, such as DnD there are two kinds of lycanthropes. Natural ones and afflicted ones. Natural ones are more powerful and can control when they turn, even during daylight. Also, this was something present in the Underdark movies as well.
But either way, lycanthropes just kick so much ass no matter what the folklore.
~wickerman~