First, identify the actors:
Then, notice that all of them have been featured on tv shows with at least one other... Next, notice that some of these tv shows are anagrammed below with an extra letter:
Smash | I | Ah miss |
Lipstick Jungle | I | Epic killing juts |
Life Unexpected | T | Exceed left input |
Designing Women | T | Ginseng downtime |
Big Love | I | Give boil |
Girls | L | Grills |
Gilmore Girls | U | Grislier mogul |
Cougar Town | I | Grow auction |
Ugly Betty | S | Guy belt sty |
Chicago Sons | I | Iconic hog ass |
Aliens in America | T | Inertial amnesiac |
Modern Family | N | Manly informed |
Swingtown | H | Nth sown wig |
Phenom | W | Own hemp |
Parenthood | A | Panda hooter |
Rhoda | G | Rad hog |
Valerie | N | Real vine |
The West Wing | O | Showing tweet |
Lost | S | Slots |
Veronica Mars | T | Storm variance |
Once Upon a Time | T | Tau omnipotence |
Sports Night | N | Thong sprints |
Star Trek: Voyager | E | Try average stroke |
Bewitched | W | We ditch web |
Samantha Who? | S | Woman has hats? |
Next, reorder the people in a circle with the common show linking them.
Judith Light | Phenom | W |
Jennifer Lien | Star Trek: Voyager | E |
Tim Russ | Samantha Who? | S |
Jean Smart | Designing Women | T |
Alice Ghostley | Bewitched | W |
Shelley Berman | Chicago Sons | I |
Jason Bateman | Valerie | N |
Valerie Harper | Rhoda | G |
Mary Tyler Moore | Lipstick Jungle | I |
Sarah Hyland | Modern Family | N |
Julie Bowen | Lost | S |
Emilie de Ravin | Once Upon a Time | T |
Ginnifer Goodwin | Big Love | I |
Tina Majorino | Veronica Mars | T |
Krysten Ritter | Gilmore Girls | U |
Scott Patterson | Aliens in America | T |
Dan Byrd | Cougar Town | I |
Matthew Perry | The West Wing | O |
Felicity Huffman | Sports Night | N |
Peter Krause | Parenthood | A |
Zosia Mamet | Girls | L |
Shiri Appleby | Life Unexpected | T |
Britt Robertson | Swingtown | H |
Jack Davenport | Smash | I |
Bernadette Peters | Ugly Betty | S |
Read off the extra letters from the anagrams, and that spells out WEST WING INSTITUTIONAL THIS... which clues the episode Institutional MEMORY... and MEMORY is the answer!