I was scanning through list of Billboard Hot 100 #1s starting from 2015 backwards and Im very much familiar with each chart topper entry until 2003. I didnt even know this went #1! And after searching it in Youtube was the first time Ive heard it Didnt watched the American of his season. Whats yours....

To help you find with your unfamiliar #1s..heres a LINK

Crack A Bottle comes to mind

I am familiar with all post 2010 but before that not so much, I've never heard Bad Day by Daniel Powter and it was supposedly very big

Seeing as there have been #1 songs on the Hot 100 since 1958 Im guessing there's plenty

All of the mid-2000's American Idol winner songs like "Do I Make You Proud," "I Believe," "Inside Your Heaven," etc. I have no idea how any of them go.

Wtf? That song was inescapable and THE biggest hit of 2006. How did you miss it?

You have to list some at least

True. #1 year ender of 2006

Black and Yellow

He might be 10-12 and was 3/4 when it was big. Its ATRL you never know

The lead single from Fifth Harmony's second album.

I was like 11 at that time but that song wasn't that big in my country and let's be honest it's beyond forgotten for a number one year-end song

If Madonna has any number ones then all of them

I've only heard like 3 or 4 songs by her

These two too

The OP and that Taylor Hicks song

How do you not know "Stand Up" or "Bad Day?"

I was 10 in 2006, but I remember it at least from American Idol

Edit: Oh you ain't American

All those hip hop 1-week #1 in the 2000s.

From this decade:

When I Was Your Man
Whistle
Black and Yellow
Imma Be
Break Your Heart
OMG