Tonight, it's the final chapter of "A Tale of Two BYU Football Teams" - the defense, which has played, ahem, at a high level; and the offense, which has not.The 7-5 Cougars take on 9-3 San Diego State in the Poinsettia Bowl (6 p.m., ESPN). Rumor is that James Lark, not Riley Nelson, will start at quarterback for BYU.We'll see.Elsewhere on TV ...A White House Christmas: First Families Remember (7 p.m., NBC/Ch. 5): Past residents of the White House remember celebrating the holidays there.The X Factor (7 p.m., Fox/Ch. 13): A winner is declared in the two-hour season finale.Project Runway All Stars (7, 8:31 and 11:02 p.m., Lifetime): The remaining designers have to create vintage 1920s looks.CMA Country Christmas (8 p.m., ABC/Ch. 4): Dierks Bentley, Lady Antebellum, Little Big Town, Martina McBride, Scotty McCreery, The Band Perry and Keith Urban are among those who perform.2012: The End Is Now (10 p.m., History): Prophecies and other baloney.Burn Notice (10 and 11 p.m., USA): Sam and Jesse are taken captive; assassins target Michael and his team.It's Always Sunny in Philadelphia (11 p.m., FX): Frank and Dennis face off. (Season finale)Jersey Shore (11 p.m., MTV): The gang prepares to say goodbye.