I don't really have a preference. For me, a dog's temperament, health, and training matter much more than whether it's male or female.
I prefer female dogs because they don't lift their legs in the house. My neighbor used to have 2 male labs and they would go down to the basement and lift their legs on the furnace. She said their home really stunk because of it so that's always in my brain when thinking about which dog I would want.
I can understand why that experience would stick with you. I have a dog too, and keeping the house clean is definitely something I consider when thinking about what kind of dog I'd prefer.
Both male and female dogs looks very cute and pretty to me. I don't have any reason why I should be specifically asking to have only male or female dogs.
I don't really mind but in most cases, I would go for a male dog first. I have this long belief that male dogs tend to outlive female dogs, although I might be wrong.