In the five years it has been on the air, The Walking Dead has broken all sorts of television-watching records—and its spinoff, Fear the Walking Dead, hit an all-time cable premiere high in August. While the zombie-filled drama was the most tweeted-about series in 2015, it wasn’t able to scare up a large enough audience to become the most watched show of the year. That honor, according to Nielsen’s year-end number-crunchers, belongs to the brains over at The Big Bang Theory. Here are the most watched television series of 2015 (football games not included).

1. THE BIG BANG THEORY

Average Number of Viewers: 21,065,000

It’s only appropriate that CBS’s hit series about a bunch of geniuses would manage to devise a way to hold on to the top spot for a second year in a row.

2. NCIS

NCIS/Facebook

Average Number of Viewers: 20,913,000

CBS continues its reign atop the Nielsen ratings with NCIS. Though the series is in the midst of its 13th season, viewers don’t seem to be tiring of Mark Harmon or his crime-solving skills.

3. THE WALKING DEAD

Average Number of Viewers: 19,669,000

In addition to being the most tweeted about show of the year, the graphic novel-turned-graphic zombie show is the only cable series to make it into Nielsen’s final tally of most-watched series.

4. EMPIRE 

Empire/Facebook

Average Number of Viewers: 17,747,000

Though its ratings took a tumble in its second season, Lee Daniels and Danny Strong’s King Lear-like series came out of nowhere in January to give Fox one of its biggest premieres, and has gone on to break a number of other television records.

5. NCIS: NEW ORLEANS

Average Number of Viewers: 17,316,000

Though it only debuted in the fall of 2014, the advantage of a built-in audience has led NCIS’s Big Easy spinoff to ratings victory.  

6. BLUE BLOODS

Blue Bloods/Facebook

Average Number of Viewers: 14,974,000

Now in its sixth season, CBS’s Tom Selleck-fronted police drama is one of the few returning series with a regularly growing audience.

7. DANCING WITH THE STARS

Average Number of Viewers: 14,555,000

It says something (positive) about our television-watching habits that ABC’s hit dance show is the only reality series on this list.