Gossip Girl (8pm, CW) - In the two-hour series finale, the gang (at right) joins forces at a party and the identity of Gossip Girl is revealed. The finale also includes memorable scenes from past seasons, plus interviews with the cast and producers.
How I Met Your Mother (8pm, CBS) - Robin takes steps to have Patrice fired from WWN, while Marshall puts a jinx on Barney.
Extreme Makeover: Home Edition (8pm, ABC) - A couple with more than 30 foster children are given a larger home.
Christmas with the Mormon Tabernacle Choir (9pm, UNC-TV) - Jane Seymour and baritone Nathan Gunn join the Mormon Tabernacle Choir and Orchestra at Temple Square for a Christmas celebration.
1600 Penn (9:30pm, NBC) - A special sneak peek at a new NBC sitcom following fictional U.S. presidential and his family. In this first episode, the president's son is caught in a public mishap and escorted back to the White House, where he's kept under close surveillance. Later, the president discusses a trade agreement with visit South American leaders. Bill Pullman plays the president and Jenna Elfman is the first lady. Adrienne has a review.
Hawaii Five-0 (10pm, CBS) - McGarrett and Catherine try to help a boy whose father disappeared and may have gotten into some deadly trouble in the backwoods of Oahu.