"Cunt" is quite an interesting one. It's an ancient word with close equivalents in other languages. Words for male genitalia seem to be far more acceptable. I can't exactly articulate why that should be, but perhaps it's to do with the fact that the male organs "stick out" and are not exactly beautiful by any objective measure I can think of, thereby providing ample material for negative connotations. Not only that, you use 'em then forget it, leaving the missus to deal with the consequences for the next nine months. On the other hand, the vagina (to quote Billy Connolly in one of his respectful moments, a beautiful place with a beautiful name), performs the wonderful physical function at the moment of birth that allows us all to be here to talk about it in the first place. A blunt word that is overwhelmingly pejorative almost every time it's uttered seems jarringly disrespectful, which is why "cunt" is often considered to be the harshest and strongest of all swear words. So the only time I ever use the word is when I'm on my own in my car with the windows up, being held up or otherwise irritated by all those dickheads, tossers, nobheads, pricks, wankers and bellends who are in my way...