The other day, I had a conversation with my parents about the cultural impact of Seinfeld and The Simpsons, and we couldn't think of any other shows that top them in that way. Old episodes of both shows are still memeable to this day.
The Simpsons have nothing on post WWII tv shows like I Love Lucy, Leave It To Beaver etc. When there were very few tv channels and after when some tv shows played on repeat forever anytime the networks needed something to fill a slot you’d get something close to saturation of knowledge of characters and situations. Even for wildly popular series like GoT this will never happen again. The consolidated audience isn’t there. For a brief post war moment there was accidentally a TV canon.
If we're talking globally though, I don't think anything has ever had (or will ever have again) the global saturation of The Simpsons. I Love Lucy and Leave it to Beaver never had international success and existed at a time when TV wasn't as globally popular. Even within the US, Leave it to Beaver never broke into the Nielsen Top 30. Meanwhile in many countries, The Simpsons got the treatment you're talking about. I grew up in Australia, where at least 7 episodes of The Simpsons have aired in primetime per week for almost 30 years, and for half that time most people only had 3 commercial channels. I just checked the TV guide, and it's running from 6:30 PM to 9 PM tonight on network TV and airing 6 episodes throughout the day on cable. If you're under 45, The Simpsons saturated popular culture during your youth, and the same is true for friends and colleagues from around the world. 40 year old Mexicans and 4 year old New Zealanders know the same show in a way that was never true for Lucy or Beaver.
Granted, I didn't grow up with Leave It To Beaver, but I don't get the sense that it had a lasting cultural impact in the same way as I Love Lucy. It seemed like by the 90's everyone viewed the show as cringe, and the few who quote it don't do so in a way that was endearing.
Someone pointed out that Cheers started great but lost its heart when Colasanto (“Coach”) passed away. It obviously lasted a long time, but it transitioned into more of a traditional sitcom.
I Love Lucy had a much bigger impact 30 years after it started than those shows, but the impact has faded. I'm only 42 and I still quote I Love Lucy all the time, because it was still in constant reruns in the 80s.
I think Simpsons might have an advantage given that it's run for 30 years.
IMO The Office is up there. It was popular in its day, but it seems to only be growing more popular on Netflix. I think it's still the most-watched show on the platform. And there are tons of memes.
