American Idol (8pm, Fox) - Auditions continue, but also, Madonna previews her new music video featuring Nicki Minaj and M.I.A.
Parks and Recreation (8:30pm, NBC) - Leslie makes it her mission to find Ann a date for Valentine's Day. Meanwhile, Ben turns to Ron for help in figuring out Leslie's elaborate Valentine scavengar hunt, and Chris is troubled by the status of his love life.
Grey's Anatomy (9pm, ABC) - In an alternate reality episode, Meredith dreams about "what ifs" in a series of flashbacks: What if her mother didn't get Alzheimers and Meredith was a happy, well-adjusted person? What if she hadn't met Derek in a bar and he stayed married to Addison? What if Alex was a geek? What if ... (Hey, at least they aren't singing in this one!).
The Union (9pm, HBO) - Cameron Crowe's tribute to the collaboration between Elton John and Leon Russell, who was John's mentor in the 1970s, as they reunite nearly 40 years later to record their 2010 album.
Daisy Bates: First Lady of Arkansas (10pm, UNC-EX) - An Independent Lens documentary looking at the life of Daisy Bates, who led the integration of public schools in Little Rock, Arkansas, in 1957. Read more about the "Daisy Bates" documentary and other air times.
The Mentalist (10pm, CBS) - A fallen fashion designer mounting a comeback is murdered, and agent Darcy continues her manhunt for Red John.
I Just Want My Pants Back (11pm, MTV) - A new series about a twentysomething navigating the ups and downs of post-collegiate life in Brooklyn. In tonight's premiere, Jason Strider has his heart -- and his most beloved pair of blue jeans -- stolen by a one night stand.