TV highlights: President Obama plays guest on 'The Colbert Report'

(All times eastern) RETURNING SHOW: "The Great Christmas Light Fight" (ABC at 8 p.m.) is back to illuminate neighborhoods across America yet again. Eight families join the competition and come armed with some special decorations worthy of the $50,000 prize, including a live animal nativity in Lebanon, Tenn., and a talking house in Rowlett, Tex.