I've always wanted to make a turducken. I have the illustrated instructions and have deboned poultry before. But that's not a meal for a small family gathering.
Also, a long time ago, I watched Jacques Pepin make a cassoulet. It was fairly complex with different meats etc. A more than one day effort. If I could find a few people who would eat it, my family would not, I'd make it for New Years.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan