I wonder if there are any here that Hengle doesn't know.  Nah, probably not.  But for the rest of us:

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List of fictional expletives

Belgium - from The Hitchhiker's Guide to the Galaxy: "The concept it embodies is so revolting that the publication or broadcast of the word is utterly forbidden in all parts of the galaxy except one, where they don't know what it means."

bitchcakes - from NewsRadio, crazy, frenetic ("he went all bitchcakes").

gimboid - from Red Dwarf; one who is stupid or clumsy; possibly an adaptation of the word gimp

mule fritters - From M*A*S*H, a Colonel Potter-ism, substitute for "bullshit".

pimhole - from A Bit of Fry and Laurie with Hugh Laurie and Stephen Fry, pimhole was used to replace c*nt and circumvent the BBC's guidelines on swearwords. Hilarious in that moral guardian Mary Whitehouse complained that the sketch was obscene, because "Everybody knew what they were talking about".

puckernuts - from Elfquest; similar meaning to "damn" or "damn it"

socktucker - from The Oscar, a trashy 1963 novel. An obvious euphemism for "cocksucker."

zarking fardwarks - from The Hitchhiker's Guide to the Galaxy: "What in the name of zarking fardwarks is the old fool doing?" spoken by Ford Prefect, about Slartibartfast... Approximate meaning: "f*ckin' hell."

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I recently overheard a chap on the bus using the phrase 'busting a grumpy', meaning to... er... poo.  It made me laugh...