Females, for sure. I've had male dogs before, and while I love them, there are a lot of qualities that I don't like aswell. I only want one more male dog in my lifetime. In 'my' breed (Toller) the females are smaller, more agile, loving but independent at the same time (males are like velcro...I like to have some space), more active, and they seem to put more 'umph' into anything they do. Though, they are more difficult to train as they aren't as willing to please as the males are but I can live with that and actually prefer it to a dog with an "I'll do anything to please you, just ask!" sort of attitude. Of course, I'm just speaking in general and this doesn't apply to all males or females but this is what I've experienced.