For me if I had to pick a good contender it would be the UK version of The Office.
I know many tend to debate how Ricky Gervais really fell off and how he repugnantly acts like a whiny centrist edgelord but me personally IMO I actually don’t think he was ever funny not even a little.
His big break through television was just so painful to sit through it’s so charismatically boring the characters are completely generic at best (notably Tim) or straight up insufferably unlikable at worst (especially the protagonist David FUCKING Brent) and most importantly the humour is just embarrassing.
Always seemed like The Thick Of It but without the nuisance tongue in cheek and charming satire.
A lot of the hype about Grease is nostalgia, no doubt about that.
But a lot of the rest is that a loooot of the songs are both catchy and very easy to understand. The movie also forms a social dynamic that is easy to understand for kids.
We learned to sing “Summer Nights” in school, and then friends and I would sing the song over and over, adding more and more childish humor that we found hilarious (because…kids). We also instantly got the implied social dynamic (boys just want to get sex, girls want to have mushy romance).