Yes, MacArthur Park is horrible. I know every word, and used to sing it gleefully off key. But earworm?
Here’s one I actually like-
You need something that has a second verse, same as the first!
And one that I like much less - but it’s hard to get out of your head-
Just gonna leave this here…
Awww come on guy’s these are all my favourite songs. 
Whhaatt these are 80’s classics. Have mercy.
Last night my wife asked me if I was ever going to stop singing Oasis songs around the house. I said maybe…
You’re right, I meant them to be good examples of biggest earworms of all time, not the meanest, nastiest, more irritating ones (I’ve filled my quota, above, for posting those!)
Every now and again these three still pop into my mind out of nowhere:
and
The Chainsmokers one is the worst TBH.
Actually, this song should be flagged! 
This thread is abuse. At least now I know who amung us are sadists. I guess that’s a good thing.
You want a German classic 
OK: 
Hey, I’m married to a Barbie, and I used to play that to get her moving when we had someplace to go. That’s not an earworm, it’s a tool!
Something with the potential to become one of these catchy tunes in the future 
.
YO, so cool MAN 
Here’s one of the “good” earworms: Blue Monday. Personally, I prefer the original 1983 12" over the later remix. I couldn’t find the right one in Songwhip, so here’s a Youtube link.
Genau. 
I agree. Have the 12” on vinyl.
Check out Happy! Season 2 on Netflix. The song is prominently featured on there.
Sorry to do this, but…
Yes, but this track is Starship’s Earworm.
@Lothar_Wolf - there’s a video for this that’s not a 90s VW commercial ?!?