Oprah Winfrey (4-5 p.m., 6ABC) - Oprah reveals her favorite things for summer; supermodel Heidi Klum provides her picks for the best swimsuits and summer gear; Mary J. Blige performs.

Dodgeball: A True Underdog Story (8-10 p.m., Fox29) - Ben Stiller's comedies usually are spotty affairs made up equally of very smart comedy and lowbrow dumb stuff, but this 2004 comedy is sweet genius from start to finish. Stiller and his inspired costars - Vince Vaughn, Rip Torn, Alan Tudyk and Mrs. Stiller, Christine Taylor - gleefully skewer the whole "plucky champion" movie genre by setting it inside the lamest sport ever devised, then playing it as if their very souls depended on the outcome.

Signs (8-10:15 p.m., TNT) - Even more than he did with his first follow-up, Unbreakable, writer-director M. Night Shyamalan proves his skill with The Sixth Sense was no fluke with this equally eerie 2002 suspense tale. Mel Gibson stars as a small-town Pennsylvania widower and ex-minister whose children (Rory Culkin and Abigail Breslin) have a better grasp than he does on the enormous crop circle that appears mysteriously on their farm. Repeats at 10:15 p.m.

Late Show With David Letterman (11:35 p.m.-12:35 a.m., CBS3) - Actress Teri Hatcher; environmentalist Robert F. Kennedy Jr.

The Tonight Show With Jay Leno (11:35 p.m.-12:35 a.m., NBC10) - Actor Matthew Fox.

Jimmy Kimmel Live (12:05-1:05 a.m., 6ABC) - Television host Ryan Seacrest; musician Clay Aiken; Kate Nash performs.

The Late Late Show With Craig Ferguson (12:35-1:35 a.m., CBS3) - Singer Reba McEntire; actor Vinnie Jones.

Late Night With Conan O'Brien (12:35-1:35 a.m., NBC10) - Wrestler John Cena; Everest performs.