Smallville (8pm, CW) - Everyone loses their memory after drinking spiked champagne, courtesy of Zatanna, at Clark and Lois's bachelor and bachelorette parties.
Who Do You Think You Are (8pm, NBC) - Kim Cattrall digs into her family roots, centering her investigation on the mysteries surrounding her grandfather. She uncovers an uncomfortable truth and forges new connections with the women in her family.
Fringe (9pm, Fox) - There's a lot of buzz about this episode, which will be heavy on flashbacks. Apparently, Walter (right) recounts the crucial period of time in the 1980s following his initial visit to the alternate universe and the ongoing Cortexiphan tests he was conducting on young children. "Fringe" fans should not miss it.
Your OWN Star (9pm, OWN) - Oprah's search for the next TV star comes to an end tonight. The two finalists must create pilots for their own shows, with Mark Burnett as their mentor, and Oprah crowns a winner.
DC Cupcakes (10pm, TLC) - In the Season 2 premiere, a 9-foot cupcake sculpture of a glow-in-the-dark guitar is constructed for a sweet 16 party. A second episode airs at 10:30.
Bar Karma (10pm, Current TV) - Sonja Sohn (Kima from "The Wire") guest-stars as “Lucy,” a famous actress who is summoned to Bar Karma in the middle of a surgical procedure. Will she make it out of the operating room alive? The star of "Bar Karma" is from Chapel Hill.
Portlandia (10:30pm, IFC) - The first season finale of the hilariously bizarre send-up of a couple of pretentious hipsters in Portland features Fred Armisen and Carrie Brownstein holding tryouts for a new Portland baseball team. Here's a sneak peek.