Oprah Winfrey (4 p.m., 6ABC) - Oprah reveals the results of the karaoke contest; actress Mo'Nique (Precious: Based on the Novel "Push" by Sapphire); journalist Anderson Cooper.

Monk (9 p.m., USA) - Monk must accompany Lt. Disher on a Scout camping trip.

Medium (9:02 p.m., CBS3) - Allison (Patricia Arquette) rents an SUV after her car is wrecked, and the new vehicle's radio has an interesting feature: It's broadcasting other people's conversations.

Numb3rs (10:02 p.m., CBS3) - Virtual reality just got a lot less virtual. Don (Rob Morrow) and the team are conducting a sting to catch a cybercrime lord, but the mission is foiled by a brilliant, charismatic hacker looking for his own piece of the online black market. There may not be any actual turf in this turf war, but there is a strong possibility of someone ending up actually dead. David Krumholtz also stars in the new episode "Shadow Markets.

Late Show With David Letterman (11:35 p.m., CBS3) - Actor Ricky Gervais; comic Brian Regan; Ralph Stanley and the Clinch Mountain Boys perform.

The Tonight Show With Conan O'Brien (11:35 p.m., NBC10) - Science challenge winner and finalists; Pixies perform.

Jimmy Kimmel Live (12:06 a.m., 6ABC) - Actor Ted Danson; TV personality Khloe Kardashian and professional basketball player Lamar Odom; Chickenfoot performs.

The Late Late Show With Craig Ferguson (12:37 a.m., CBS3) - Actor Ewan McGregor; Regina Spektor performs.

Late Night With Jimmy Fallon (12:37 a.m., NBC10) - Actress Rosie O'Donnell; actor Ian Somerhalder.