The Secret Life of The American Teenager (8 pm/ET ABC Family)
The big moment is finally here: Amy gives birth to her son in the first-season finale of this successful teen drama. And now the show transitions from being about a pregnant teenager to focusing on a teenage mom - an adjustment that proves difficult for Amy. New dad Ricky, however, faces less of a struggle as he forms a bond with "stepdad" Ben and enjoys the time he spends visiting his son. Meanwhile, Anne and Amy will be spending less time with George and Ashley, as the latter two are moving out.
* Heroes (9 pm/ET NBC)
Now that Danko has outed Nathan as "one of them," he sets his sights on another thorn in his side: Rebel. On Noah's questionably trustworthy advice, Danko releases Tracy in hopes that she will lead them to Rebel. But will the mysterious and seemingly all-knowing figure take the bait? Meanwhile, Swoosie Kurtz enters the Heroes universe, playing an old friend of Angela's who helps the Petrelli matriarch while she's on the run.
* 24 (9 pm/ET Fox)
As the clock strikes 10pm, Jack has been framed for two murders, and FBI orders are to shoot him on sight. Still, our hero did catch one break when he took out the hit man that Starkwood sent to kill Jack and Sen. Mayer. (Don't you just hate it when the bad guys and the good guys want to shoot you?) From the hit man's cell phone, Jack got the shipyard location where Starkwood's bioweapons are arriving, and he and Tony are on the way. As FBI agent Moss said in the last hour, "It is impossible to overestimate Jack Bauer."
* Roommates (9 pm/ET ABC Family)
In the series premiere of this New York City-set sitcom that borrows a page from Friends, a group of twentysomethings attempt to navigate postcollege life. Mark (Tyler Francavilla) bumps into Katie (Dorian Brown), his old high-school crush, and decides to move in with her and her roommates. Still harboring feelings for Katie, Mark's plan is to win her over. But he'll get no help in that endeavor from Hope (Tamera Mowry), Katie's best friend and roommate, who doesn't take a liking to Mark upon meeting him.
* Jon & Kate plus 8 (9 pm/ET TLC)
If you've read the gossip rags lately, you're probably aware of the elephant in the room: rumors that Jon and Kate's marriage is in trouble. Is there any truth behind them? Find out when they address the issue in the Season 4 finale. On a lighter note, the season wraps up with two back-to-back new episodes, which follow the family to a Harlem Globetrotters game and to Philadelphia's Please Touch Museum, where kids are actually encouraged (gasp!) to play with the exhibits.