What are the songs that SMASHED at time of their release and that now, are completely forgotten?

The obvious answer to me is One More Night.
The fact it stayed 9 weeks at #1...

Britney's hits, there's a reason why almost all her songs get absolutely no recurrent play.

Scream & Shout.

The fact that it blocked Gangnam Style is still just

And the fact that Harlem Shake was a multiple-week #1 despite it not being a tenth as big as Gangnam Style


And now that i said that, Harlem Shake could be considered a "smash" based on its chart performance, and is now completely forgotten, so that

Scream & Shout, Born This Way, Part Of Me, Boyfriend.

Hey Soul Sister

One Sweet Day.

ten million weeks at #1 and now....

I have literally never heard that song in my life and wouldn't even know about it if not for ATRL.

"The fact it stayed 9 weeks at #1"

fff really?

Part of Me

Yet somehow have great VEVO views, the best of her peers in fact.

.

I don't even know this song.

Not really. I still hear this on the radio

I genuinely hear Part of Me on the radio all the time, still. I do agree that it's not as remembered as a lot of her other singles though. It's just not completely forgotten.
-
"We Are Never Ever Getting Back Together" - Taylor Swift (I think IKYWT grabbed everyone's attention & over-shadowed it despite not peaking as high as it.)

?

Born This Way, Part of Me, Till the World Ends, Hold it Against Me

Baby one more time and basically all of Britney's hits pre 2008 are almost completely forgotten imo

One Sweet Day is a perfect example.

The delusion. Most of her pre-VEVO hits have at least 40 Million views, which is the same or more than some actually "remembered" hits by other people