Mad Men and American Horror Story lead the nominations at this year's Emmy Awards with 17 each.

The advertising drama is hoping to gain its fifth Best Drama win, which would make it the only series ever to have won the accolade that many times. At present it is level on four victories with Hill Street Blues, L.A. Law and The West Wing. Other nominees in the same category are Breaking Bad, The Good Wife, Game of Thrones, Boardwalk Empire, British Drama Downton Abbey and newcomer Homeland. Downton Abbey - which was awarded Best Miniseries in 2011, but has switched categories for 2012 - picked up 16 nominations.

Jimmy Kimmel stepped in to announce the nominees at 05:40 am this morning in Los Angeles, stepping in for Nick Offerman, who was delayed by weather problems. As he took to the stage in his pyjamas, alongside actress Kerry Washington, the talk show host asked, "Is this a sex dream?"

Jimmy gave the nominations for Outstanding Lead Actor in a Drama Series, which sees Boardwalk Empire star Steve Buscemi face off against Dexter actor Michael C. Hall, Bryan Cranston from Breaking Bad, Hugh Bonneville from Downton Abbey, Mad Men lead Jon Hamm and Damian Lewis, star of Homeland.

Lead Actress in a Drama Series pits The Good Wife star Julianna Margulies against Michelle Dockery from Downton Abbey, Elisabeth Moss from Mad Men, Kathy Bates from Harry's Law, Homeland star Claire Danes and Damages actress Glenn Close.

The Outstanding Comedy Series 2012 section was populated by mostly familiar shows, with 30 Rock, Curb Your Enthusiasm, Modern Family and The Big Bang Theory all picking up nods, joined by newcomers Girls and Veep.

Jimmy will also host the Emmy awards at the Nokia Theatre in Los Angeles on September 23, which will also be broadcast live.