TONIGHT'S MUST-SEES

"The Big Bang Theory," 7 p.m., CBS. The season's funniest new comedy offers an especially promising episode. Preparing for the Physics Bowl, the guys decide Sheldon (Jim Parsons) is just trying to prove he's smarter than them. They replace him with his nemesis, Leslie Winkle. She's played by Sara Gilbert ("Roseanne"), who has had some fine moments on the show.

"High School Confidential," 10 p.m., WE. This smart series, following Kansas classmates for four years, has a strong hour. Shortly after his wife died, Rick re-married. His daughter, Cate, suddenly had a much more strict stepmom — and had a classmate as her stepsister. Every relationship shattered; some were rebuilt. For counterpoint, "Confidential" views a classmate who had family warmth and high achievement.

OF NOTE

"Dancing With the Stars," 7 p.m., ABC. Priscilla Presley is gone, leaving seven celebrities. Now they face a group number, in addition to their duets.

"Bones," 7 p.m., Fox. When a college basketball star is killed, Booth and Brennan question his girlfriend, his coach, even his replacement on the team.

"American Experience: Roberto Clemente," 9 p.m., PBS. Roberto Clemente entered a 1950s base-ball world that lacked diversity. He spoke little English; others spoke no Spanish. He rarely bonded with Pittsburgh teammates, but lifted the once-lowly Pirates to two World Series championships. It is a fascinating story, even though this documentary is poorly crafted and, at times, maddeningly vague.

"Medium," 9 p.m., NBC. Allison's health deteriorates as she faces unsolved cases and a dream about Scanlon's death.