The last time I skimmed the thread, I think I saw "f***wit". I like it, too... For some reason, it seems so much more hateful and diminishing than any other combination of words including "f***".
"f***ing" in my household is another word for "um", though, so I'm not really phased by much of them. I guess "f***wit" seems so harsh because it's so uncommon to hear it where I live.
I recall some discussion about the word "c***", too. Not sure who decided this was the most offensive four-letter word in the English language, at least by American standards... I heard it in music and movies from people living across the pond all the time, so the apparent shock value is entirely lost on me.