Monty Brinton, Cbs
Britney Spears and Josh Radnor on "How I Met Your Mother," which airs at 7:30 p.m. on Ch. 2.

Big Bang Theory (7 p.m., Ch. 2): Leonard and Sheldon lie to Penny to try to spare her feelings.

Canterbury's Law (7 p.m., Ch. 13): The deputy attorney general wants to jail Elizabeth.

How I Met Your Mother (7:30 p.m., Ch. 2): Britney Spears tries to prove she's not crazy by doing a guest shot on this sitcom. She plays a receptionist who has her eye on Ted.

Two and a Half Men (8 p.m., Ch. 2): Rose returns to care for bedridden Charlie.

Frontline (8 p.m., Ch. 7): Bush's War is a two-part, 4 1/2-hour report on the Iraq war. (Concludes Tuesday.)

New Amsterdam (8 p.m., Ch. 13): John recalls his substance abuse problems — back in the early '60s.

New Adventures of Old Christine (8:30 p.m., Ch. 2): Christine is jealous of Barb and Matthew's time together.

CSI: Miami (9 p.m., Ch. 2): A woman is shot to death in the middle of her wedding to a pro baseball player.

Medium (9 p.m., Ch. 5): Allison's dreams relate to Cynthia's daughter, who has been missing for 10 years.

Greek (9 p.m., ABC Family): The second season of this show about college kids begins.