“30 Rock” (9:30 p.m., NBC): On “30 Rock,” Jack begins to freak out after

“30 Rock” (9:30 p.m., NBC): On “30 Rock,” Jack begins to freak out after Avery (guest star Elizabeth Banks) breaks the news that a cable company wants to buy NBC. Meanwhile, Liz believes she has found Mr. Right in the waiting room at her dentist’s office.