20. John Krasinski as Jim Halpert (The Office)

PARK CITY, UT - JANUARY 22: Actor John Krasinski attends the "Nobody Walks" premiere during the 2012 Sundance Film Festival held at Eccles Center Theatre on January 22, 2012 in Park City, Utah. (Photo by Jemal Countess/Getty Images)

19. Craig T. Nelson as Zeek Braverman (Parenthood)

HOLLYWOOD - NOVEMBER 10: Actor Craig T. Nelson arrives at "The Company Men" screening during AFI FEST 2010 presented by Audi held at Grauman's Chinese Theatre on November 10, 2010 in Hollywood, California. (Photo by Alberto E. Rodriguez/Getty Images for AFI)

18. Frank Gwynne as Herman Munster (The Munsters)

17. John Mahoney as Martin Crane (Frasier)

LOS ANGELES - SEPTEMBER 21: Actor John Mahoney attends the 55th Annual Primetime Emmy Awards at the Shrine Auditorium September 21, 2003 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

16. James Avery as “Uncle” Philip Banks (The Fresh Prince of Bel-Air)

BEVERLY HILLS - OCTOBER 1: Actor James Avery attends the Light the Way for Lupus Los Angeles benefit at the Beverly Hills Hotel October 1, 2003 in Beverly Hills, California. The event was sponsored by the Lupus Research Institute. (Photo by Frederick M. Brown/Getty Images)

15. Tim Allen as Tim Taylor (Home Improvement)

CULVER CITY, CA - APRIL 17: Actor Tim Allenl speaks during the Eighth annual TV Land Awards on April 17, 2010 in Culver City, California. (Photo by Frederick M. Brown/Getty Images)

14. Jesse Tyler Ferguson and Eric Stonestreet as Mitchell Pritchett and Cameron Scott Tucker (Modern Family)

BEVERLY HILLS, CA - JANUARY 14: Actors Jesse Tyler Ferguson and Eric Stonestreete attend BAFTA Los Angeles' 18th annual Awards Season Tea Party held at Four Seasons Hotel Los Angeles at Beverly Hills on January 14, 2012 in Beverly Hills, California. (Photo by Frazer Harrison/Getty Images For BAFTA Los Angeles)

13. Conrad Bain as Phillip Drummond (Diff’rent Strokes)

HOLLYWOOD - MARCH 2: Actor Conrad Bain attends the TV Land Awards 2003 at the Hollywood Palladium on March 2, 2003 in Hollywood, California. (Photo by Robert Mora/Getty Images)

12. Jerry Stiller as Frank Costanza (Seinfeld)

NEW YORK - OCTOBER 29: Jerry Stiller attends the 12th Annual Project A.L.S. New York City Benefit "Tomorrow Is Tonight" at Lucky Strike Lanes & Lounge on October 29, 2009 in New York City. (Photo by Larry Busacca/Getty Images)

11. Reginald VelJohnson as Carl Winslow (Family Matters)

UNIVERSAL CITY, CA - APRIL 19: Actor Reginald VelJohnson arrives at the 7th Annual TV Land Awards held at Gibson Amphitheatre on April 19, 2009 in Universal City, California. (Photo by Jason Merritt/Getty Images)

10. Andy Griffith as Sheriff Andy Taylor (The Andy Griffith Show)

9. Michael Gross as Steven Keaton (Family Ties)

HOLLYWOOD, CA - MARCH 01: Actor Michael Gross arrives to 'Tim And Eric'$ Billion Dollar Movie' Los Angeles Premiere at ArcLight Hollywood on March 1, 2012 in Hollywood, California. (Photo by Alberto E. Rodriguez/Getty Images)

8. Hugh Beaumont as Ward Cleaver (Leave It To Beaver)

7. Alex Karras as George Papadapolis (Webster)

TITLE: WEBSTER (US TV SERIES) • PERS: KARRAS, ALEX • YEAR: 1983-1987 • REF: TVW006AE • CREDIT: [ THE KOBAL COLLECTION / ABC-TV ]

6. Michael Landon as Charles Ingalls (Little House On The Prairie)

5. Dan Lauria as John “Jack” Arnold (The Wonder Years)

LOS ANGELES - MARCH 06: Actor Dan Lauria attends Crown Royal and Tab Energy Drink's Cool Down Post Award Season Party hosted by director Paul Haggis and actor/recording artist Chris "Ludacris" Bridges at the Beverly Towers Penthouse on March 6, 2006 in Los Angeles, California. (Photo by David Livingston/Getty Images)

4. Bob Saget as Danny Tanner (Full House)

NEW YORK - NOVEMBER 06: Comedian/actor Bob Saget attends "Cool Comedy - Hot Cuisine" presented by the New York Comedy Festival at Carolines on Broadway on October 06, 2007 in New York City. (Photo by Scott Wintrow/Getty Images)

3. Robert Reed as Mike Brady (The Brady Bunch)

2. Tom Bosley as Howard “Mr. C” Cunningham (Happy Days)

BEVERLY HILLS, CA - DECEMBER 1: Actor Tom Bosley attends the Sixth Annual Family Television Awards at the Beverly Hilton Hotel on December 1, 2004 in Beverly Hills, California. (Photo by Frederick M. Brown/Getty Images)

1. Bill Cosby as Heathcliff “Cliff” Huxtable (The Cosby Show)

CHARLESTON, : Entertainer Bill Cosby salutes as he descends the capitol stairs in Charleston, West Virginia, 27 October, 2000. Cosby was one of the speakers prior to a campaign rally by Democratic presidential candidate US Vice President Al Gore. AFP PHOTO Mike NELSON (Photo credit should read MIKE NELSON/AFP/Getty Images)