* Survivor: Heroes vs. Villains (8/7c CBS)
The granddaddy of reality shows, which debuted on May 31, 2000, celebrates its 20th edition with 20 former players who became famous either for their heroic efforts or villainous ways. They first arrive in Samoa via helicopters and are divided into their respective "good" and "evil" tribes before taking part in the initial immunity challenge and attending the first tribal council, where one player's attempt at revenge or redemption will come to an abrupt end. Among the castaways are previous game winners Tom Westman, Parvati Shallow and J.T. Thomas, and last season's breakout personality and runner-up to the title, Russell Hantz.
* Grey's Anatomy (9/8c ABC)
It's Valentine's Day, but love isn't exactly what's in the air around the hospital after a restaurant roof collapses, and the hot docs have lots of work to do. Still, this is Grey's Anatomy and, sure enough, something might be stirring between Bailey and Ben (Jason George), the anesthesiologist she sparred with last week. As for Mark and Lexie, it looks bad (and he's preoccupied with daughter Sloan). But there was that elevator scene last week, so the final word on Mexie has yet to be written.
* The Office (9/8c NBC)
A rattling Sabre has teeth in the wake of the mysterious company's strategic acquisition of Dunder Mifflin. The corporate curtain rises for new CEO Jo Bennett (Kathy Bates), who arrives in Scranton and awes the staffers with her magnetic swagger and charismatic Southern style. But this belle rings loudly: She resists the Dunder Mifflin notion of having two branch managers, a policy shift that sorely impacts Michael and Jim. One remains captain; one must step down and return to salesman duty. Meanwhile, a Valentine's Day plan blows up on Andy.
* In Performance at the White House (8/7c PBS)
President and Mrs. Obama host a White House celebration of the civil-rights movement that features renditions of the era's memorable songs and readings from important speeches and writings. Among the artists taking part: Yolanda Adams, the Blind Boys of Alabama, Natalie Cole, Bob Dylan, Jennifer Hudson, John Legend, John Mellencamp, Sweet Honey in the Rock founder Bernice Johnson Reagon, Smokey Robinson and Seal. Speakers include Morgan Freeman and Queen Latifah.
For a series that shamelessly traffics in potty humor, it's not too surprising that Sarah would finally get her own show for the toilet-training set. It comes about after her craving for a pancake brunch is spoiled by a kiddie-lit reading, and just like child's play, Sarah's on the air with a new target audience of wee ones. Of course, her chief antagonist, Jay, joins a group opposed to her brand of entertainment, which leads to a debate on Real Time with Bill Maher (who appears as himself).