The Big Bang Theory: Sheldon (Jim Parsons ) and Leonard (Johnny Galecki) have a big blow-up on a new episode of the sitcom (8 p.m. CBS).
Guinness World Records Gone Wild: Everyday folks attempt outrageous stunts like hammering nails into their heads and swallowing lighted candles in this new series (8 p.m. Tru).
Parks and Recreation: Unlucky-in-love Ann (Rashida Jones) comes to a decision in this new episode (8:30 p.m. NBC).
Two and a Half Men: "My Name Is Earl's" Jaime Pressly guest stars on a new episode (8:31 p.m. CBS).
The Office: Dunder-Mifflin-ites resort to trickery to take advantage of Valentine's Day deals in this new episode (9 p.m. NBC).
Person of Interest: The team's latest target is a tech billionaire on this new episode of the drama (9:01 p.m. CBS).
King of the Nerds: Jason Mewes and Kevin Smith — a.k.a. "Clerks'?" Jay and Silent Bob — serve as guest judges in this new episode of the reality competition (10 p.m. TBS).
Elementary: John Hannah ("Spartacus: Blood & Sand") guest stars on a new episode of the mystery-drama (10:01 p.m. CBS).
BrandX With Russell Brand: The British actor-comic is back with new episodes of his late-night show (11:31 p.m. FX).
The Sting: Robert Redford and Paul Newman star in this classic 1973 caper set in 1930s Chicago (7:45 p.m. TCM).
Chronicle: Three high-school buddies develop superpowers in this edgy 2012 thriller (8:30 p.m. HBO).
College basketball: Indiana plays Illinois (4 p.m. ESPN); Clemson faces Virginia (4 p.m. ESPN2); the UCLA Bruins host Washington (6 p.m. ESPN); Missouri meets Texas A&M (6 p.m. ESPN2).
Basketball: The Lakers visit the Celtics (5 p.m. TNT) and the Bulls battle the Nuggets (7:30 p.m. TNT).
Hockey: The Kings play the Predators (5:30 p.m. FSN).