"The Big Bang Theory" 8 p.m. CBS — When Sheldon's childhood hero seeks Leonard's help, Sheldon decides to befriend Bill Nye.
"Grey's Anatomy" 9 p.m. ABC — Strife builds between Meredith and Cristina.
"Glee" 9 p.m. Fox — The glee kids figure out if they're more like Katy Perry or Lady Gaga.
"The Crazy Ones" 9:01 p.m. CBS — Sydney's enamored ex-coworker writes a song about her.
"Two and a Half Men" 9:30 p.m. CBS — Walden invites Lynda Carter ("Wonder Woman") to dinner.
"Scandal" 10 p.m. ABC — Olivia's team continues to work with Josie, whom Cyrus and Mellie scheme to take down.
"Elementary" 10:01 p.m. CBS — Sherlock's brother arrives in New York.
