Official NBC Synopsis:
Hailed by Entertainment Weekly as not only “the best comedy on TV this year” but “simply the best TV,” the Emmy Award-winning comedy “30 Rock” is told through the comedic voice of Golden Globe winner Tina Fey (“Liz Lemon”) and features Golden Globe winner Alec Baldwin (“Jack Donaghy”) as a top network executive and Tracy Morgan (“Tracy Jordan”) as the unpredictable star of Lemon’s hit variety show, “TGS with Tracy Jordan.” Lemon constantly has her hands full, juggling corporate interference from Donaghy and off-the-handle star antics from Jordan, all while attempting to salvage her own personal life.

Blerg (Liz Lemon's favorite expletive)
The Rural Juror (Jenna's hard-to-pronounce film)
Frank's hats (Judah Friedlander designs a new hat for his character to wear in each episode. Each one is a trucker hat with some sort of slogan on it)
Devon Banks' (Will Arnett) obsession with Kenneth (Jack McBrayer)
Mind grapes (... this one's hard to explain)

The show has amassed quite a list of generally good guest stars. Here is a list of some of them.
Appearing in Character
Wayne Brady as Steven Black
Matthew Broderick as James Riley, also known as "Cooter Burger"
Steve Buscemi as Lem
Tim Conway as Bucky Bright
Rachel Dratch as, well, a bunch of people in a bunch of episodes
Edie Falco as Congresswoman Celeste "C.C." Cunningham (D-VT)
Carrie Fisher as Rosemary Howard
Buck Henry as Dick Lemon
Nathan Lane as Eddie Donaghy
Chris Parnell as Dr. Leo Spaceman
Paul Reubens as Gerhardt Habsburg
Andy Richter as Mitch Lemon
Isabella Rossellini as Bianca
Molly Shannon as Katherine Catherine
David Schwimmer as Jared a.k.a. Greenzo
Elaine Stritch as Colleen Donaghy
Rip Torn as Don Geiss
Dean Winters as Dennis Duffy
Appearing as Themselves
New York Mayor Michael Bloomberg
Tucker Carlson
James Carville
Al Gore
Chris Hansen
Rob Huebel
Chris Matthews
John McEnroe
Conan O'Brien
Jerry Seinfeld
Meredith Vieira
Whoopi Goldberg
Maury Povich
Ghostface Killah
Gladys Knight

Season 1:
Pilot (10.11.06)
The Aftermath (10.18.06)
Blind Date (10.25.06)
Jack the Writer (11.1.06)
Jack-Tor (11.16.06)
Jack Meets Dennis (11.30.06)
Tracy Does Conan (12.7.06)
The Break Up (12.14.06)
The Baby Show (1.4.07)
The Rural Juror (1.10.07)
The Head and the Hair (1.18.07)
Black Tie (2.1.07)
Up All Night (2.8.07)
The “C” Word (2.15.07)
Hardball (2.22.07)
The Source Awards (3.1.07)
The Fighting Irish (3.8.07)
Fireworks (4.5.07)
Corporate Crush (4.12.07)
Cleveland (4.19.07)

Season 2:
SeinfeldVision (10.04.07)
Jack Gets in the Game (10.11.07)
The Collection (10.18.07)
Rosemary's Baby (10.25.07)
Greenzo (11.09.07)
Somebody to Love (11.15.07)
Cougars (11.29.07)
Secrets and Lies (12.06.07)
Ludachristmas (12.13.07)
Coffee & TV (01.10.08)
MILF Island (4.10.08)
Subway Hero (4.17.08)
Succession (4.24.08)
Sandwich Day (5.1.08)
Cooter (5.8.08)

Season 3:
Do-Over (10.30.08)
The One with the Cast of Night Court (11.13.08)
Gavin Volure (11.20.08)
Reunion (12.4.08)

Tina Fey (Liz Lemon)
Alec Baldwin (Jack Donaghy)
Tracy Morgan (Tracy Jordan)
Jane Krakowski (Jenna Maroney)
Scott Adsit (Pete Hornberger)
Jack McBrayer (Kenneth the Page)
Judah Friedlander (Frank)
Katrina Bowden (Cerie)
Keith Powell (Toofer)