This is the one I usually respond with.....
Hello, my name is DK and I suffer from guilt for not forwarding 50 billion FUCKing chain letters sent to me by people who actually believe if you send them on, a poor six year old girl in Scotland with a breast on her forehead will be able to raise enough money to have it removed before her redneck parents sell her to a travelling freak show. And, do you honestly believe that Bill Gates is going to give you, and everyone to whom you send "his" email, $1000? How stupid are we?
Ooooh, looky here! If I scroll down this page and make a wish, I'll get laid by a model I just happen to run into the next day! What a bunch of bullshit.
Maybe the evil chain letter leprechauns will come into my house and sodomize me in my sleep for not continuing a chain letter that was started by St Peter in 5AD and brought to this country by midget pilgrim stowaways on the Endeavour.
Fuck 'em!! If you're going to forward something, at least send me something mildly amusing. I've seen all the "send this to 10 of your closest friends, and this poor, wretched excuse for a human being will somehow receive a nickel from some omniscient being" forwards about 90 times. I don't fucking care. Show a little intelligence and think about what you're actually contributing to by sending out these forwards. Chances are, it's our own unpopularity.
The point being? If you get some chain letter that's threatening to leave you dateless or luckless for the rest of your life, delete it. If it's funny, send it on. Don't piss people off by making them feel guilty about a leper in Botswana with no teeth who has been tied to the backside of a dead elephant for 27 years and whose only salvation is the 5 cents per letter he'll receive if you forward this email.
Now forward this to everyone you know. Otherwise, tomorrow morning your underwear will turn carnivorous and will consume your genitals.
Have a nice day.