I've had both in the past, now I have three dogs and I prefer them. If and when the time comes to have more dogs then my preference would definitely be males.
I've had four bitches, two lots of two, first two bitches put up with each other most of the time but were never ever friends, hated each other for years and needed to be kept apart. Second set were an accident, both rescues, lurcher and greyhound, never separated, couldn't keep them apart, a pair of book-ends, constantly together.
Now I have three boys (all castrated) and their friendship is just fantastic, they've all bonded and gel together and it's just lovely to watch - and, more importantly, there's absolutely no jealousy between them, and they love us both. I also think that, like all good males should, they should learn to listen to us females and do as they're told, first time and every time.
*now runs off to hide*