May sweeps aren't what they used to be, but signs of hoopla linger. Cristina mulls her future on two successive episodes of "Grey's Anatomy" (7 p.m., r, and 8 p.m., ABC, TV-14), setting up that character's departure from the series.
Actress Sandra Oh has been nominated for five Emmys for her role as Cristina Yang. She will appear on tonight's "Jimmy Kimmel Live" (10:35 p.m., ABC), along with "Science Bob" Pflugfelder and Boy George.
Not that long ago, May sweeps used to bring the final few hours of "24" on Fox. The network is rebooting the ticking-clock nail-biter in a 12-part miniseries, which kicks off next Monday with the two-hour premiere of "24: Live Another Day." When "24" debuted, Jack Bauer seemed like a 21st-century revival of James Bond. The title of this series has 007 written all over it. There's even a Union Jack in the show's poster. Can martinis and atrocious puns be far behind?
Look for Jack Bauer (Kiefer Sutherland) on "Late Night With Seth Meyers" (11:35 p.m., NBC), along with Rose Byrne and Richard Ayoade. Mary Lynn Rajskub, the comic actress who plays Bauer's sidekick, Chloe, sits down with Jimmy Fallon on "The Tonight Show" (10:35 p.m., NBC), along with Andrew Garfield and Chvrches.
Fans of FX's "Louie" are in luck. The series returns next Monday. Some may remember that his fictional character auditioned to replace a retiring David Letterman. We all know that didn't work out.
The real Louis C.K. appears on "Late Show With David Letterman" (10:35 p.m., CBS), where he will be subjected to a performance from the Broadway cast of "Rocky."
• A series that features the epic storylines, dramatic intrigue and special effects magic that were once the hallmarks of sweeps specials, "Vikings" (9 p.m., History, TV-14) ends its second season tonight.
Not to give too much away, but I've long thought of this season as "The Godfather, Part II" of Norse sagas. As things began, we saw that, like Michael Corleone, Ragnar (Travis Fimmel) had alienated his wife, Lagertha (Katheryn Winnick), and his brother, Rollo (Clive Standen).
Now, the eccentric Floki (Gustaf Skarsgard), part mystic ship-builder and part court jester, has grown disenchanted with Ragnar. Like Fredo Corleone, he feels overlooked and disrespected, and he's ripe for exploitation by the cunning King Horik (Donal Logue). I guess that makes Horik the Hyman Roth character here. Except Horik's impetuous anger almost got everybody killed. So that makes him a little like Sonny Corleone as well.
OK, "Vikings" is ridiculously violent. Some of the dialogue is a little too on the nose: ("I hope our God and your God can be friends ...") But any show or saga that could inspire so many "Godfather" comparisons bears watching. And rewatching.
• Toni and Candace attend a feminist retreat on the season finale of "Portlandia" (9 p.m., IFC, TV-14).
• Encore dedicates the month of May to superhero movies, the kinds that attract millions to cineplexes, particularly in warm weather. As somebody who stopped being 12 years old some years back, I've never exactly warmed to the genre. I haven't felt compelled to see a "Batman" (7 p.m., Encore) remake since this adaptation from 1989, directed by Tim Burton and starring Michael Keaton and Jack Nicholson.
Tonight's other highlights
• Professor Proton mentors Sheldon on "The Big Bang Theory" (7 p.m., CBS, TV-PG).
• Pop performances on the "iHeartRadio Music Awards" (7 p.m., NBC), presented live.
• A baker's dozen tackles Southern cuisine to win a trip to Las Vegas on "Hell's Kitchen" (7 p.m. Fox, TV-14).
• Results are read on "American Idol" (8 p.m., Fox, TV-PG).
• Jack suggests that Rachel take up wrestling on "Surviving Jack" (8:30 p.m., Fox, TV-14).
• A crisis inspires collaboration with Mycroft on "Elementary" (9 p.m., CBS, TV-14).
• A nanny hallucinates on "Black Box" (9 p.m., ABC, TV-14).
Lana Turner and Sandra Dee star in the 1959 tearjerker "Imitation of Life" (7 p.m., TCM).
Marcos has a plan on "The Vampire Diaries" (7 p.m., CW, TV-14) ... Nathan suspects Tom's date's motives on "The Millers" (7:30 p.m., CBS, TV-PG).
Gretchen insists on Alan's honesty on "Two and a Half Men" (8 p.m., CBS, TV-14) ... Mary sheds blood for Scotland on "Reign" (8 p.m., CW, TV-14) ... A student recoils when Meredith sets her eyes on her father on "Bad Teacher" (8:30 p.m., CBS, TV-PG).
David Spade is scheduled on "The Daily Show With Jon Stewart" (10 p.m., Comedy Central) ... Martin Short and Kelis appear on "Conan" (10 p.m., TBS) ... Tyler Glenn, Ben Gleib, Arden Myrin and Tone Bell are booked on "Chelsea Lately" (10 p.m., E!) ... Saul Williams sits down on "The Colbert Report" (10:30 p.m., Comedy Central) ... Katt Williams, Amy Purdy, Derek Hough and Hezekiah Walker are booked on "The Arsenio Hall Show" (syndicated) ... Craig Ferguson hosts Cheryl Hines and Quinton "Rampage" Jackson on "The Late Late Show" (11:35 p.m., CBS).