Dancing with the Stars (8pm, ABC) - Season 13 opens with 12 new celebrities competing, including Chaz Bono, Ricki Lake, Ron Artest, Nancy Grace, David Arquette, and Hope Solo.
How I Met Your Mother (8pm, CBS) - The seventh season opens with two new back-to-back episodes. The mystery wedding prompts the friends to reminisce about things. Also, Marshall gets his dream job but is terrified videos from his past will crush his hopes.
The Sing-off (8pm, NBC) - In the Season 3 premiere, 8 a cappella groups perform. Sara Bareilles joins Ben Folds and Shawn Stockman on the judging panel.
Two and a Half Men (9pm, CBS) - In part one of Season 9's two-part opener, Ashton Kutcher joins the cast as brokenhearted billionaire Walden Schmidt. It is widely rumored that tonight's show will also kill off Charlie's Sheen's character.
2 Broke Girls (9:30pm, CBS) - A new series about two struggling waitresses at a Brooklyn diner who are trying to save enough money to open their own cupcake shop. Adrienne has more info.
Roast of Charlie Sheen (10pm, Comedy Central) - After you finish watching the sitcom Sheen was fired from, you can tune in for the star's scathing "salute." Roasters include Jeffrey Ross, Anthony Jeselnik, Steve-O, Harvey Levin, and Mike Tyson.
Castle (10pm, ABC) - Are we really worried that Beckett didn't survive last season's gunshot cliffhanger? No. What we really want to know is if she heard Castle tell her he loves her after she was shot. In addition to the personal drama, there's the hunt for the sniper who tried to kill her. Also, there's a new by-the-book captain in charge (Penny Johnson Jerald, "24"), and she's not too fond of Castle hanging with the cops.
The Playboy Club (10pm, NBC) - A new series set in the legendary Playboy Club in 1960s Chicago. Tonight, high-powered attorney and club key holder (Eddie Cibrian) comes to the aid of a new Bunny after she's assaulted by the leader of a the Bianchi crime family. Worth checking out?
Hawaii Five-O (10pm, CBS) - The second season begins with McGarrett in prison awaiting trial for the governor's murder. Meanwhile, Kono is suspended from the force, pending an internal investigation for allegedly stealing department money.