Horde Mode

A mode in the big hit game, Gears Of War 2, and quite possibly the best idea anyone has come up with in the realm of infuriating time wasters that you play with (up to) four other people online, simply to successfully clear waves 1 through 50 to get an X-Box 360 achievement for 30 measly Gamer Points, just to have your best friend call you up asking if you want to do it all over again.