Sure, I could make it number one on my list (previous post) but that is too obvious...
We did this in a couples setting two years ago, some good friends and others we were still getting to know better...and it is now legend!
The mystery auction game ended up being so much fun! By not telling anyone exactly what the game was and making it mysterious, I had the whole anticipation thing and the surprise factor of it. And the fact that they didn't have to shop but donated a couple bucks at the door was a positive too.
I bought and re-gifted a variety of small and cheap gifts (can of wd40, pens, etc) with some bigger, more expensive, funny gifts (huge pink bra with a roll of toilet paper, Christmas boxers). There were more presents then people. I wrapped all of them in plain brown paper. Each person had been given monopoly money ($11) at the door in an envelope with their name on it. Throughout the night, people could win different amounts for different things to add to their original amount. For instance, the first people to arrive and the last people to arrive received $5. The tallest elf and the shortest elf received $1 each, and so on.
After mingling and eating for awhile we circled up and we explained that the mystery game actually was an auction for the gifts which would take place after we gave the chance for a few more people to earn some more money. We then voted on the most merry outfit and least Christmasy outfit, the worst Christmas gift story, the most romantic gift, etc. And to top it off we played a guys vs. girls Catch Phrase with the winning team each getting $5. We pulled out the pile of gifts and put them in the middle of the floor and Big D served as our auctioneer (he and I didn't participate in the bidding since we knew what we had).
He played it up and described the gifts but wouldn't let them touch them. When a gift was finally bought, that person had to open it and show it off. At any time in the game, anyone could make an offer on that opened gift. Sometimes the offers were lower and other times higher so the original winner of the gift had potential to "make" money on it. And you could offer on as many gifts as you had money for, so potentially people could leave without a gift or with several.
Just one word of warning...be prepared for pranks. Our neighborhood now see's us in a whole different way.
We found our bush in the above state of dress after church on Sunday. It had been snowing so hard when I left that I had not even noticed it.