Thursday, Nov. 25 It’s Thanksgiving, and besides pretending that the parade is more interesting than it actually is, or having awkward interaction with relatives, there’s another great holiday tradition: reality TV marathons. The Mythbusters gang tests myths all day long [Discovery, 9 a.m. to 8 p.m.], and those 11 hours are followed by the two-hour “Punkin Chunkin” competition—yes, it involves chucking pumpkins—hosted this year by Adam Savage and Jamie Hyneman. Food Networks’ Ace of Cakes is ending after its upcoming 10th season , but TLC’s similar Cake Boss is still around and will air all day on Thanksgiving, if you want to get into a cake mood [TLC, 6 a.m. to 3 a.m.]. If you just want to celebrate your inner glutton, watch Adam Richman eat on Man v. Food [Travel Channel, 9 a.m. Thursday to 4 a.m. Friday]. But if you’d rather be inspired to clean, check out Clean House ’s marathon [Style, 6 a.m. Thursday to 3 a.m. Friday]. If you need to cheer yourself up after all the family che...