I have seen many fans (exo-l's & vip's) both saying their group was top boy group. Bb fans say they were 2 gen group who had superior concert and sales and were wold wide stars. And they were loved by general SK public (according to vip's) Exo fans say they revived dying physical market and were perfect boy group (according to exo-l's). Things which worked against BB was amount of scandals which were termed 'criminal' according to SK law and BB had handful of those and are still facing few of them but lets let touch that. Things which worked against exo was Chinese members leaving with law suits and all the mess it created, even one or more members had dating scandals in very early stage of their idol career which somehow effects idols. According to people who dont like BB, their success was all media plays by Yg and they were not enough popular as they were claimed to be, those people say BB tours were media olayed a lot and the revenue and attendance provided from official yg outlets were wrong. They also point that most of money which BB earned was by illegal or club activities. According to people who dont like exo, they never got any better after growl, they say that song made them popular with adding the fact that they were from big 3 and were seen as next Tvxq, sm was never able to replicate that success and exo was only fandom driven because of similarities between them and tvxq. I believe Tvxq had more impactful career than both of above groups and were totally top group during their prime (before lawsuit and members leaving). Let me see who you think was top boy group during that time, and lets be civil. EDIT1:- lets add 2Pm in this list too, they were really popular but kinda underrated because their company never braged about their achievements.