Cursing out the Jehovah's Witness that came to the door and telling him/her that you're a devil worshiper.
It was fun when I was 9 and it's still fun at 23.
Originally Posted by Vannah
My variant on that--my then-wife and I had just moved into the neighborhood, and a delegation from the local Baptist church came knocking on the door:
Delegation Leader: Hi! We're with the 69th Baptist Church here, and we noticed you're a new neighbor, so we'd like to welcome you to come join us for Sunday worship this weekend.
Me: Oh, thank you for the invitation. I'd really like to, but I'm afraid that if I do they'll depose me from the high priesthood of my Satanic coven. I'm afraid I'll have to decline your kind invitation.
Let's say they didn't find any reason to stay and engage in idle chit-chat.
Almost as funny (though ultimately sad) was the day a couple Jehovah's Witnesses came knocking, and our dog (a 90+ pound German Shepherd bitch) went apeshit in the storm door; the Witnesses immediately looked terror struck and backed away relatively quickly. It really was something of a hoot to watch them try to pitch their tracts and copies of
The Watchtower onto our porch from about 45 feet away (it didn't work very well). I suspect they'd had dogs set on them multiple times.
Cheers,
bcg