"Into the new world " : Kpop anthem
"Gee" : Kpop legendary song
"Oh" : i think everybody know the Oh oh, ah ah, many many, and the choregraphy, popularize the cheerleader concept
"Genie" : i don't think this song need explanation, people still talk about it nowadays, the leg dance took asia by storm
"I got a boy" : It's the song of reference when people are talking about experimental and is every year talk about how they bring the 3 songs in one trend with this song
Honestly i really try to think but honestly i can't find any Group who had as much iconic song
who even after all this years are still heard a lot or a lot of people are making reference to it