Don't miss the season première of this intense reality show. Cameras follow the daily activities of the doctors, nurses and patients at New York Presbyterian Hospital and Newark's University Hospital, and there's never a dull moment. ABC, 9 p.m.
The stakes have been raised -- again -- for the rebel forces trying to defend Earth from alien invaders as the sci-fi hit's fourth season begins. Noah Wyle returns as college professor turned resistance leader Tom Mason; Winnipegger Sarah Sanguin Carter is also back as rebel warrior Maggie. Super Channel, 8 p.m.
Oliver is promoted to acting staff sergeant in the episode Heart Breakers, Money Makers. Meanwhile, Andy is assigned the task of training the Division's greenest rookie, Duncan Moore. ABC, 8 p.m.
George Stroumboulopoulos: Kris Holden-Reid
David Letterman: Mark Ruffalo
Jimmy Fallon: Jennifer Lawrence, Craig Robinson
Jimmy Kimmel: Bob Newhart, Nicola Peltz
Craig Ferguson: Jane Lynch, Keke Palmer
Seth Meyers: Jonah Hill, Laura Dern
Jon Stewart: Melissa McCarthy
Conan O'Brien: Joel McHale, Freddie Wong & Matt Arnold