Ellen Pompeo in ‘Grey’s Anatomy’; Rocky Carroll in ‘NCIS’; ‘Cocomelon’

Liliane Lathan/ABC; 2023 CBS Broadcasting; Courtesy Of Netflix

Somewhere in the United States, someone is probably watching an episode of Grey’s Anatomy right now, or if not, an installment NCIS. Someone under age 7 is likely streaming Cocomelon.

Nielsen began releasing its weekly streaming charts three years ago, and in the 157 weeks since then, those three series have made the rankings more than any other titles on any streaming platform. In fact, not a single week has passed since the first chart (released Sept. 3, 2020, and covering the week of Aug. 3-9) that didn’t feature at least one of Grey’s Anatomy, NCIS or Cocomelon.

Grey’s Anatomy also owns the longest streak of consecutive weeks making the top 10. The show, which streams on Netflix, appeared on the very first ranking and stayed present through all of 2021 and 2022 before finally falling out of the top 10 acquired series the week of May 8-14, 2023 — a run of 144 weeks. The medical drama has appeared in 153 of the 157 Nielsen streaming rankings as of publication.

NCIS (136 weeks straight, 147 overall) and Cocomelon (135 weeks, all consecutive) could pass the Grey’s benchmark in a couple of months if they continue to make the rankings, as they have every week since the beginning of 2021.

Analyzing the three years of the rankings (which only cover TV-set viewing in the United States), a few patterns become clear. The most obvious one is that because of the way Nielsen calculates streaming viewing — the total time spent watching all episodes of a series — shows with big libraries have a distinct advantage. Of the 12 titles that have spent the most time in the rankings, six (Grey’s, NCIS, Criminal Minds, Supernatural, Gilmore Girls and The Big Bang Theory) are current or former broadcast series with at least 150 episodes each. A seventh, Heartland, has been running in Canada since 2007 and has more than 230 episodes available to streaming users south of the border.

Even without a big bank of episodes, however, four titles have made the streaming rankings continually thanks to a ton of repeat viewing — largely by kids. Cocomelon, which is aimed at preschoolers, is on a 135-week run in the top 10 acquired series despite only having about 20 hours’ worth of programming on Netflix, but it’s 20 hours that young kids watch over and over (and over and over and over). Similarly, Bluey’s catalog of 140 episodes on Disney+, each running about eight minutes, adds up to a little less than 19 hours, but it’s one of only two kids’ series ever to top a billion minutes of viewing for a single week in the Nielsen rankings (the other was The Legend of Korra in August 2020).

Disney movies Moana (84 weeks in the top 10 films list) and Encanto (58 weeks) — the only two feature films in the 12 most consistent titles — also benefit from repeat viewing. The threshold for making the top 10 movies in Nielsen’s rankings is also typically lower than for series, which is no surprise given that a feature film is a couple hours’ worth of viewing compared to dozens or hundreds of hours of running time for a series.

Only one original streaming series ranks among the 12 most consistently ranked shows, and that comes with a catch. The Great British Baking Show is a Netflix original outside the U.K., but it’s produced by Channel 4 in its home country and airs there first a few days before streaming in the United States. It’s also among the few Netflix shows whose new seasons stick to a weekly release pattern (again, owing to its origins as an over-the-air show in the U.K.) and has a larger library than a lot of other original shows.

In general, though, original series — whether released all at once, weekly or somewhere in between — tend to burn hot and bright for a while before falling out of the rankings between seasons. The Crown has the most weeks in the top 10 (38) of any original series after The Great British Baking Show, and Stranger Things owns the longest run of consecutive weeks in the rankings at 19.

Stranger Things, however, only has one other week in the top 10 to its name for a total of 20, and another huge show, Ozark, has just 25. That’s due to the fact that each has had only one new season in the three years of the Nielsen rankings; the rest came well before the weekly charts debuted.

The 12 shows and movies that most consistently show up in the Nielsen streaming top 10s are below.