Definitely a male. I have owned a female dog and though she was great & i bonded very well with her, I just have a special place in my heart for male doggies.
Now aside from other animals besides dogs, I will NEVER own another female horse. Oh my goodness, that was a nightmare lol. I definitely prefer geldings over mares. Other than dogs and horses (and of course, my cat Peanut, who is a male), I don't know much about sexes in other animals.
But males are the way to go for me. Males tend to bond better with me and I like the overall look of a male dog over a female. I like my dogs to be more...masculine looking (if that makes sense).