The Sing-Off The Sing-Off

The Sing-off
8/7c NBC
Eight a cappella groups from around the country assemble to kick off NBC's four-night singing competition. The groups don't use backing bands or tracks but instead use their voices to create a rich and full sound. On hand to critique the performances are celeb judges Ben Folds, Shawn Stockman (of Boyz II Men) and Nicole Scherzinger. But viewers have the ultimate say in who advances as they cast votes for their favorite groups. The winner receives a recording contract and a $100,000 prize. — Brie Hearn

Jennifer Hudson: I'll Be Home for Christmas

8/7c ABC
Jennifer Hudson, the American Idol finalist who vaulted to stardom as an Oscar and Golden Globe winner in the 2006 hit film Dreamgirls, returns home to Chicago to celebrate the joys of Christmas. Hudson performs "The Christmas Song," "O Holy Night" and "Silent Night." She is also joined by fellow Grammy winner Michael Bublé on seasonal favorites "Baby It's Cold Outside" and "Let It Snow." — Fred Mitchell

Two and a Half Men
9/8c CBS
Carl Reiner has pushed himself to do just about everything in the entertainment industry, but he won't have to make a great leap or work too hard for his role in this episode, playing a legendary TV producer whom Evelyn invites to Charlie's for Christmas dinner. Meanwhile, Jake's girlfriend is away for the holidays, so Charlie teaches Jake the one thing he knows well: the art of infidelity. — Bill Ecklund

CSI: Miami
10/9c CBS
Eric Delko (Adam Rodriguez) is no longer a CSI, but tonight he returns to the courtroom. Unfortunately, he's not there to help out his former colleagues. Instead, he appears as an expert witness hired by the defense to help free a suspect nabbed by Horatio. And to make the situation even more uncomfortable, Eric scrutinizes Calleigh's evidence-gathering abilities. We guess this means the two former lovers won't be getting back together again anytime soon. — Tim Holland

Anatomy of a Pandemic
9/8c PBS
As pandemics go, the outbreak of the H1N1 flu has, thankfully, thus far been something of a dud, far less of a threat than the influenzas of 1957 and 1968 let alone 1918, when an estimated 50 million people died worldwide. In this report, Ray Suarez details how the U.S. and world governments have been fighting H1N1 and compares this pandemic to past influenza outbreaks. He also looks at the 1976 swine-flu scare and the ill-fated, government-mandated vaccine program that did more harm than good. — Jeff Gemmill

Vampire Diaries
8/7c CW
For fans who may have missed an episode or two, or for folks who haven't yet tuned in, the CW is allowing viewers to sink their teeth into its bloody hit series this week by reairing all 10 of its fall episodes, two back-to-back per evening. Of course, for devotees who have already savored these 10 hours, it's a great opportunity to relive the romance and the horror that are its hallmarks. In tonight's pilot, Stefan (Paul Wesley), a 161-year-old vampire who doesn't look a day over 19 and refuses to drink human blood, returns to his Virginia hometown to pursue a high-school student (Nina Dobrev) who reminds him of a long-lost love. — Tim Holland