What's Worth Watching: American Idol, The Big Bang Theory, Mom and more for Thursday, February 25

Matt Roush
Kelly Clarkson After American Idol
Fox

American Idol (8/7c, Fox): The original American Idol, Kelly Clarkson, returns to show the new kids on the chopping block how it's done as the final season reveals its Top 10 in the first live episode. Besides performing, Kelly joins judges Keith Urban, Jennifer Lopez and Harry Connick Jr. in providing feedback and, perhaps, even constructive criticism.

The Big Bang Theory (8/7c, CBS): Adam West, TV's original Batman, almost steals the show as an invited—make that paid—guest at Sheldon's (Jim Parsons) birthday party, which coincides with the hit sitcom's 200th-episode milestone. It's the first time he's allowed his circle of friends to celebrate the day, because of painful childhood memories. As recurring guest stars Christine Baranski (wonderfully acerbic as Leonard's mom), Wil Wheaton, Sara Gilbert and others gather to try to ease Sheldon's party-panic anxiety, this becomes one of the sweetest, funniest episodes in a long while. A fitting tribute to a great character and a modern classic comedy.

Mom (9/8c, CBS): The situation's a bit more serious, up to a point, on Mom, as the support group—minus Marjorie (Mimi Kennedy), who's still steamed they didn't tell her about Jodi's (Emily Osment) death at her wedding—tries to take their mind off tragedy by indulging Bonnie (Allison Janney) in a caper that involves smuggling an illegal, though non-toxic, substance across the Canadian border. Before long, though, they're laughing through their tears.

Inside Thursday TV: With Super Tuesday looming, a newly reduced slate of Republican contenders for the presidential nomination gather in Houston for the latest GOP debate (8:30/7:30c, CNN's networks and Telemundo), moderated by Wolf Blitzer with assists from Maria Celeste Arras, Hugh Hewitt and Dana Bash. Should be fiery. ... Maybe April (Sarah Drew) wasn't quite so annoying back in the day. We'll find out when ABC's Grey's Anatomy (8/7c) flashes back to when April first met Jackson (Jesse Williams). … There's an unpleasant flash-forward on The CW's DC's Legends of Tomorrow (8/7c), when the time-tripping team lands in 2046 Star City, which is even darker and more dangerous than the version typically seen on Arrow. … BBC America's new crime drama, Prey (10/9c), unfolds over two three-part stories, starring Rosie Cavaliero as a dogged Detective Sergeant tasked to investigate cases involving possible police corruption. John Simm and Philip Glenister from the original Life on Mars co-star as her prey. … Sherlock (Jonny Lee Miller) learns the identity of his mother on CBS's Elementary (10/9c) as he looks deeper into the attempted murder of his father, Morland (John Noble). A tangled web, indeed.