The highly-popular series averaged 9.1 million viewers for season six, and its latest finale, which aired last Sunday (03Apr15), drew 18.4 million in audience totals.

"We know how rare it is to have the number one show on television for four years running and to share a season six finale on AMC with more than 18 million fans, to say nothing of the passionate and appreciated conversations that followed," president of AMC, SundanceTV and AMC Studios Charlie Collier said. "So, as we close this season, first and foremost, a heartfelt 'thank you' is on all of our minds..."

The ranking puts the show over other top contenders, including Sunday Night Football, Empire, and The Big Bang Theory.

The season finale of the zombie apocalypse series ended to mixed reviews last weekend after TV show bosses introduced comic book villain Negan, who is played by Jeffrey Dean Morgan, and left fans wondering which of their favourite characters had met their demise at the hands of his barbed-wired bat. Fans will have to wait to find out as the show doesn't return to U.S. TV until October (16).