@futurebird I'm making a lot of assumptions about what you define as popular to hit the lowest common denominator.
Queen's Bohemian Rhapsody. As far as I can tell, it's one of the last songs of its kind to gain enough popularity that I could sing the first line and be pretty confident the other person will know the song.
Fuck, this is a hard one to decide on since the most popular band I listen to barely breaks into the million views/listens/etc category. Animal's As Leader's The Problem of Other Minds. I regret part of it is a desperate wish to see more diversity in my favourite genre but also because I think they're pushing the genre is ways that are highly technical while still sounding beautiful to people who aren't trained musicians in a way we rarely see outside of Classical music.
You wouldn't think it if you listened to some of his newer music (his sound got a lot more accessible as time went on IMO) but in an effort to not spend too long on this one, I'm going with Igorrr's Melting Nails. I'm a sucker for someone taking something batshit, seemingly just throwing shit at the wall, and making it into something that works. And that's like 75% of his sound. Aside from Savage Sinusoid, his music is usually too weird for me to recommend.