The answer to this really depends on the breed you are thinking of. As a dog breeder, I usualy find that many folks THINK they want one sex over the other because the ASSUME that one sex is easier, but in reality, it could be the opposite for any given breed. For example, I breed and show terriers. Most terrier breeds are ver active and independant, but for the most parts the females are much more so than the males. For that reason, I usually reccomend males to the people who are looking for a dog who is going to be dependant on them and more affectionate. I do find terrier females to be better watch dogs though. For breeds like a Lab or Golden, the opposite is true. So choose your breed first, and go to a responsible breeder who will help you determing not only which gender, but which individual dog might be the best choice for you. A responsible breeder should be doing temperament tests etc, to help in making that determination.