Horton Hears a Who! (8pm, NBC) - A 2008 computer-animated Hollywood update of the beloved illustrated children's book by Dr. Seuss. Horton, a thoughtful elephant living in the jungle of Nool, discovers that an entire society -- Whoville -- rests inside a speck. He gentle rests it on a clover flower and searches for a place where it will be safe from the perils of the world.

How the Grinch Stole Christmas! (8pm, ABC) - Another Dr. Seuss adaptation. This is Seuss' 1957 story about the Christmas-loving Whos of Whoville (see above) and the evil Grinch who hatches a plan to steal their holiday. Boris Karloff narrates this animated classic, which first aired in 1966.

How the Grinch Stole Christmas (9pm, ABC) - Yet another Dr. Seuss adaptation, this one a live-action version of Seuss' classic tale starring Jim Carrey, Jeffrey Tambor and Christine Baranski. Directed by Ron Howard.

National Lampoon's Christmas Vacation (9pm, ABC Family) - Family man Clark Griswold (Chevy Chase) is determined to stay at home and provide a warm, fun-filled Christmas for his family.

Rizzoli & Isles (9pm, TNT) - Dr. Hope Martin asks Maura a life-changing favor in the Season 3 finale. Meanwhile, Casey Jones prepares for surgery and Tommy shows off baby T.J.  Before long, all attention turns to the collapse of a building, where loved ones are trapped inside.

Leverage (10pm, TNT) - Looks like this Season 5 finale is also the series finale. In tonight's last episode, which was filmed as a series finale, Nate takes on a case connected to his son's death and leads the team into one of its most perilous schemes. The show's executive producer describes the episode as "the most powerful episode we've ever done."

Disney Parks Christmas Day Parade (10am, ABC) - Scotty McCreery, Justin Bieber, Cee Lo Green, Jennifer Hudson, and Christina Aguilera headline this holiday extravaganza at Disney's Florida and California theme parks.

The Polar Express (8pm, ABC Family) - The animated story of an 8-year-old boy who's whisked to the North Pole by a mysterious train conductor. Features the voices of Tom Hanks and Peter Scolari.

How the Grinch Stole Christmas (8pm, ABC) - The animated Dr. Seuss tale abut the Whos and the evil Grinch with a plan to steal their beloved Christmas holiday. Boris Karloff narrates.

Dr. Seuss' How the Grinch Stole Christmas (8:30pm, ABC) - The live-action version of the original classic, starring Jim Carrey as the coldhearted Grinch trying to thwart Whoville's Christmas celebration.

Charlie and the Chocolate Factory (9pm, Disney) - Don't get excited, it's the 2005 remake with Johnny Depp, not the 1971 Gene Wilder classic. But it's still not bad.

Downton Abbey (9pm, UNC-TV) - In part 3 of 4 parts, the rivalry between Mary and Edith reaches a fever pitch, and Thomas and O'Brien plot against Mr. Bates while Anna's fondness for him grows.

National Lampoon's Christmas Vacation (10pm, ABC Family) - Family man Clark Griswold (Chevy Chase) tries for a fun-filled family Christmas at home, but things don't work out quite the way he hopes.

Christmas Unwrapped (8pm, Discovery) - The history of Christmas and how the beloved holiday changed the world, from its impact on the end of slavery to the invention of the artificial heart.

How the Grinch Stole Christmas (8pm, ABC) - The Dr. Seuss tale about the Christmas-loving Whos of Whoville and the evil Grinch who tries to steal the holiday. This 1966 classic is narrated by Boris Karloff and features songs by Dr. Seuss (Theodr Seuss Geisel) and Albert Hague. Keep your ears open for Thurl Ravenscroft (aka Tony the Tiger) singing "You're a Mean One, Mr. Grinch."

Dr. Seuss's How the Grinch Stole Christmas (8:30pm, ABC) - After the classic animated version there's the 2000 live-action version with Jim Carrey in Oscar-winning makeup as the wicked green creature. It's not without merit, but the original is better (and shorter). You should probably just watch them both. Directed by Ron Howard and starring Christine Baranski and Jeffrey Tambor.