Greater Boston 7 p.m. WGBH (Channel 2) A look at Ballot Question 3: Should we legalize medical marijuana in Massachusetts?
PBS NewsHour Debates 2012: Presidential Debate at the University of Denver 9 p.m. WGBH (Channel 2) President Obama and Mitt Romney discuss domestic policy at the first presidential debate.
Bargains 7:30 p.m. WCVB-TV (Channel 5) A constantly changing consignment shop, rugs and appliances, and more.
Boston Public Radio noon WGBH-FM (89.7)
Radio Boston 3 p.m. WBUR-FM (90.9)
NightSide With Dan Rea
8 p.m. WBZ-AM (1030) Reaction to the first Obama-Romney debate.
NEWS & TALK SHOWS
CBS This Morning at 7 a.m. on Chs. 4 and 12.
Good Morning America at
7 a.m. on Chs. 5, 6, and 9.
Today at 7 a.m. on Chs. 7 and 10; 10 a.m. on Ch. 7. Jackie Evancho performs.
Live! With Kelly and Michael at 9 a.m. on Chs. 5 and 9;
10 a.m. on Ch. 10. Tom Selleck; Heart performs.
The Ricki Lake Show at 11 a.m. on Ch. 25. Female sexuality.
The View at 11 a.m. on Chs. 5, 6, and 9. Jenny McCarthy.
The Talk at 2 p.m. on Chs. 4 and 12.
Anderson Live at 3 p.m. on Chs. 12 and 25.
Katie at 3 p.m. on Chs. 5 and 9; 4 p.m. on Ch. 6.
The Ellen DeGeneres Show at 4 p.m. on Chs. 5, 9, and 10.
Greater Boston at 7 p.m. on Chs. 2 and 11; midnight on
Conan at 11 p.m. and 1 a.m. on TBS. Ashley Greene.
The Daily Show With Jon Stewart at 11 p.m. and 1 a.m. on COM.
Colbert Report at 11:31 p.m. and 1:30 a.m. on COM.
The Tonight Show With Jay Leno at 11:34 p.m. on Chs. 7 and 10. Carol Burnett; Lang Lang and students perform.
Late Show With David Letterman at 11:35 p.m. on Chs. 4 and 12.
Jimmy Kimmel Live at midnight on Chs. 5, 6, and 9.
Late Night With Jimmy Fallon at 12:37 a.m. on Chs. 7 and 10.
The Late Late Show With Craig Ferguson at 12:37 a.m. on Chs. 4 and 12.
Last Call With Carson Daly at 1:36 a.m. on Chs. 7 and 10.
Borderline 8 p.m., midnight (LMN) Life unravels for a prison psychiatrist (Gina Gershon). R (2002)
Brokeback Mountain 8 p.m. (SHO2) Heartbreaker about two gay cowboys who fall in love in 1963 Wyoming. Heath Ledger. R (2005)
Cruel Intentions 8 p.m.,
10 p.m. (OXY) A high-school heartthrob bets he can bed a virginal classmate. Sarah Michelle Gellar. R (1999)
The Fifth Element 8 p.m.,
11 p.m. (AMC) A 23rd-century cabbie and an alien try to save the world. Striking visuals. Bruce Willis. PG-13 (1997)
Happy Endings 8 p.m. (SUND) Californians’ lives interconnect in this polyglot, multi-plot character study. Lisa Kudrow. NR (2005)
The Twilight Saga: Eclipse
8 p.m. (TMC) Bella (Kristen Stewart) faces a decision that could result in a war between werewolves and vampires. PG-13 (2010)
Pretty Woman 8:30 p.m. (FAM) Stellar fairy tale stars Julia Roberts as a hooker transformed by a corporate raider. R (1990)
The Sitter 8:30 p.m. (HBO) Irresponsible babysitter Noah (Jonah Hill) takes a trip to NYC with his three young charges. R (2011)
The Crimson Wing: Mystery of the Flamingos 9 p.m., 11 p.m. (APL) A look at a crimson-winged flamingo chick struggling to survive in northern Tanzania. G (2008)
The Lord of the Rings: The Return of the King 9 p.m. (STARZ) Frodo (Elijah Wood) is tempted by the power of the ring in the Oscar-winning finale. PG-13 (2003)
Must Love Dogs 9 p.m. (E) Amiable but bland romantic comedy about a divorcee wading into the dating pool. Diane Lane. PG-13 (2005)
Doppelganger 9:40 p.m. (FLIX) A woman is pursued by her ghostly double. Drew Barrymore. R (1993)