* The New Adventures of Old Christine (8 pm/ET CBS)
Solid? Dependable? A "rock"? Doesn't sound much like Christine, but that is exactly what a fellow scatterbrained mom (the always hilarious Kristen Johnston) considers her to be. At first, Christine takes to the compliment and the new friendship, but she soon tires of being the responsible one. It was only a matter of time.
* American Idol (9 pm/ET Fox)
Thirteen is the lucky number. In an unforeseen twist last week, the Top 12 was upped to a Top 13, and that baker's dozen sang through showcases last night. In tonight's accompanying results show, we'll discover who advances and who must face the music and bid adieu. And Idol chatter has it that Kelly Clarkson - whose star rose from Idol, of course - will take to the stage to render "My Life Would Suck Without You," plus Kanye West is slated to perform his tune "Heartless."
* Ghost Hunters (9 pm/ET Sci Fi)
The reality show's fifth-season premiere is one for history buffs. TAPS venture to Glen Mills, Pa., to probe a house built in 1695, and they document disembodied voices, phantom footfalls and unaccountable magnetic fields. Then the team visits Philadelphia to investigate the home of that famous seamstress Betsy Ross, the mother of our star-spangled banner.
* Chopping Block (8 pm/ET NBC)
Celebrated chef and restaurateur Marco Pierre White, who has appeared on the UK version of Hell's Kitchen, is no stranger to reality TV or to conflict in the kitchen. Known for his quick temper (not unlike his former mentee Gordon Ramsay), White uses his quiet form of intimidation to guide 16 aspiring restaurateurs, who are split into two teams and assigned to open competing restaurants. In the opener, the teams plan and prepare their menus and have their first encounters with a food critic.
* South Park (10 pm/ET Comedy Central)
School is back in session at South Park Elementary as Cartman, Kyle, Stan, Kenny and the gang return for a 13th season. And since the show is nothing if not topical, including last season's Chinese takeover of the U.S. and, on a lighter note, the High School Musical craze, could these crafty kids have an answer this time around for the nation's economic woes? Well, why not? At this point, anything is worth a try, even if it comes from cartoon characters.