I actually studied the practices of male and female circumcision (sometimes called FGM for "female genital mutilation") in one of my anthropology courses. The differences between the two are actually quite striking, which led me to put my vote in as opposing only female circumcision.
In male circumcision, there have been proven health benefits of having the practice done. For example, it is easier to maintain personal hygene after undergoing the process, and urinary tract infections decrease significantly, as well as other less common health problems. Also, in some cultures, women (and some men) prefer males who are circumcised to those who are not for "aesthetic" reasons.
Female circumcision, on the other hand, is a practice that is considered in many Western countries as barbaric. It consists of anything from minor surgical alterations to the female genitalia to complete removal of some parts and sewing up of the rest. It is primarily practiced in Islamic countries in Africa and some Middle Eastern ones, if I remember correctly, as well as southeast Asia. Contrary to male circumcision, FGM has the tendency to create significant medical problems, and physical pain for the woman during intercourse (which is one of the main reasons the practice is utilized). However, despite feminist movements in many of these countries, some women chose to continue the practice voluntarily because it conveys a certain measure of respect due to the fact that it preserves their chastity. And when women have been denied the option, some choose to practice it privately under questionable conditions, leading to death in some cases. This shows that it is a deeply ingrained part of the cultures in which it is practiced, and outlawing it is impractical.
Personally, unless his religion forbids it, I think all males should be circumcised because of the health benefits. It should be a matter of individual preference, but that presents the problem of people doing it soon after birth. In the case of female circumcision, which is done to pre-pubescent girls, I think it should be a matter of personal choice because they are of the age where they can decide for themselves.