Actress January Jones, of the drama series "Mad Men" arrives at the 64th Primetime Emmy Awards in Los Angeles September 23, 2012.[Photo/Agencies]

The "Mad Men" of US television and the crazy couples who make up "Modern Family" seek to retain their Emmys on Sunday when the TV industry hands out its highest honors to the year's best shows, actors and writers.

The stars and creators of dozens of comedies, dramas and variety shows gather in Los Angeles for the 64th Primetime Emmy Awards celebrating the best of television. Hosted by comedian Jimmy Kimmel, the ceremony will be shown live on ABC television.

More than 20 Emmy Awards will be handed out on Sunday night, with all eyes on the top prize - best drama series - where stylish 1960s-era advertising show "Mad Men," with 17 nominations, faces tough competition as it tries for a fifth straight win.

Industry pundits say "Downton Abbey," the PBS English period drama about the lives of aristocrats and their servants, has a good chance of snatching the trophy. Six members of its large cast also have acting nominations.

Showtime's "Homeland", a CIA thriller set in post-9/11 America, is also seen as a strong challenger, with stars Claire Danes and Damian Lewis both nominated for acting Emmys.

Lavish Prohibition-era gangster show "Boardwalk Empire" on HBO, AMC's dark drug drama "Breaking Bad," featuring three-time Emmy winner Bryan Cranston, and the warring medieval knights and kings of "Game of Thrones" (HBO) round out the drama series nominees.

"The drama series category is loaded with high-quality shows that are firing on all cylinders," said Todd Gold, executive editor of Xfinity TV.

In the comedy series race, ABC mockumentary "Modern Family", featuring the chaotic lives of three related couples and their children, is widely expected to win for a third straight year, and pick up supporting-actor Emmys for one or more of its cast.

The contest for best comedy actress is much closer. Lena Dunham, 26, the breakout young star, writer and director of HBO comedy "Girls," and Zooey Deschanel ("New Girl") take on old hands Tina Fey ("30 Rock"), Julia Louis-Dreyfus ("Veep") and 2010 Emmy winner Edie Falco ("Nurse Jackie").

Melissa McCarthy, who won in a 2011 upset for the CBS show "Mike & Molly," is back for a second shot, while Amy Poehler is also in the running for NBC's "Parks and Recreation".

In the popular reality competition slot, "The Amazing Race" has dominated the Emmys for 12 years, but "The Voice", "Top Chef", "Project Runway", "Dancing with the Stars", and "So You Think You Can Dance" are all looking for an upset.

Awards watcher Tom O'Neil, of website goldderby.com, said viewers were in for an exciting night.

"The Emmys are always packed with upsets. They are the opposite of the Oscars. There is a jaw dropper every 10 or 15 minutes with the winners and they put on a hell of a show," O'Neil said.

British actors are also expected to do well on Sunday. Maggie Smith is seen as a front-runner for supporting actress for her acid-tongued dowager countess in "Downton Abbey," while Benedict Cumberbatch is tipped to take home the miniseries actor Emmy for his modern twist on fictional detective Sherlock Holmes in the PBS/BBC drama "Sherlock," which is also a best miniseries contender.