There are many subtleties in the male sexual response that are lost to circumcision, including all estrogen receptors, apocrine glands, the penilo-cavernosus reflex (a psychosexual response triggered by stretch receptors in the frenar band), and literally tens of thousands of specialized sexual nerve endings (see http://www.norm.org/lost.html). Conservatively speaking, none of these are absolutely necessary for sexual function. But as a male, shouldn't a full range of the sexual response should be your birthright?
15 police officers killed in Colombia helicopter crash (Reuters)
from the article: An end to the agony