Do you like the wholesale destruction of everything you cherish? Do you like roguelikes? Then you're in luck because two new roguelikes are yours to play, the zombie-apocalypse city survival fest Rogue Survivor, and the Gamma Worldesque ASCII-Fallout-analogue Caves of Qud. Both are still in beta, both will keep you away from the dinner table over the holidays.
Skid MK is a fiendishly addictive and entertaining Mario Kart clone which has already taken up far too much of my week. Developers Conix Games also made a top-down zombie shooter in the Robotron tradition called Daytraders of the Dead, which is just about as addictive.