'PARKS AND RECREATION': Andy, Ben and Leslie travel to San Francisco in the Season 6 closer at 8 p.m. on NBC. (Steve Jennings/NBC)

FINALE WATCH: After Leslie revealed last week that she’s pregnant and having triplets (!) on “Parks and Recreation” (NBC at 8 p.m.), the fan-favorite wraps up its sixth season with Leslie, Ben and Andy in San Francisco for a national parks conference and the return of Tammy 2. First lady Michelle Obama guest-stars.

Sheldon attempts spontaneity for the first time in his life, and it causes friction between Penny, Bernadette and Amy on “The Big Bang Theory” (CBS at 8).

The contestants pair up to create a new twist for pizza on “Hell’s Kitchen” (Fox at 8).

“The Vampire Diaries” (CW at 8) has Enzo learning about what happened to his long-lost love in the 1960s by way of flashbacks from election night.

Jackson has to deliver the doctors some bad news, and Richard surprises Catherine in Boston on “Grey’s Anatomy” (ABC at 9).

“Saturday Night Live” (NBC at 9) comes to Thursday night with a two-hour special of the most memorable SNL digital shorts, which are likely to include “Natalie Raps” starring a rapping Natalie Portman and the Lonely Island’s “I’m on a Boat.”

“American Idol” (Fox at 9) boots off another contestant in this 30-minute results show, leaving just five singers to battle it out for the title.

SERIES PREMIERE: Reviewed by TV critic Hank Stuever on Page C1, “Bad Teacher” (CBS at 9:30) stars Ari Graynor as a takeover for Cameron Diaz in a spin-off from the 2011 film.

SERIES PREMIERE: Also reviewed by Stuever, the ABC drama series “Black Box” (10) is about a brilliant neurosurgeon’s struggles with bipolar disorder.

The return of Mycroft signals a new rift between Sherlock and Joan on “Elementary” (CBS at 10), and an investigation into unmanned aeronautics begins.

“Chicagoland” (CNN at 10) shows Mayor Rahm Emanuel delivering his annual budget address and first lady Michelle Obama visiting a young, college-bound, Chicago-area student.

Television personality Phil McGraw and actor James Van Der Beek are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), along with music from Courtney Barnett with Steven Tyler and Joe Perry.

Actors Neil Patrick Harris and Sarah Hyland come to the “Late Show With David Letterman” (CBS at 11:35), with musical guest Ray LaMontagne.

Actress Julie Bowen and stand-up comedian Dave Attell swing by “Jimmy Kimmel Live” (ABC at 11:35), with a musical performance from Cut Copy.

Rachel Lubitz