If a song is hit it doesn't mean that it's iconic, y'all don't even think before you post.
When it comes to Single Ladies, it was definitely iconic more than anything Rihanna has done. I mean it doesn't matter if Rihanna had hits bigger than Single Ladies, but she has never made such a strong impact on the general public.
The craze about the video was overwhelming, you had celebrities posting videos of them mimicking the choreo, the "put a ring on it" line was everywhere, you can still see the influence today in a lot of vines or parodies.