My kids did get some 40k stuff, and I'd made 40k advent calendars. The theme this year was board games. Between my kids, wife and myself we just go Lego Minotaurs, Lego Creationary, Munchkin, Primordial Soup, Settlers of Catan, Forbidden Island, and Castle Ravenloft. Other bits too, but I'm really looking forward to some of these games. We've already tried the two Lego games. Minotaurs is great if you want something nice and confrontational, plenty of opportunity to mess with people. Creationary is good for getting inspired, need to be quick with your fingers. Both well recommended.
Its a Festivus Miracle. Happy Holiday of your choice all.