If binary star never broke up, would they be considered the best hip-hop duo ever?

no.

^^
No

As far as groups go, I have to agree with fred. But with duo's I think they would be third best, right behind Blackstar and Outkast. Too much talent in groups for Binary Star to compete with groups, but they would have, nonetheless, reached legendary status, if they haven't already.

For duo's, I think two groups had better debuts, Blackstar and Southern...

If only they had stayed together though.

well..IDK but theyd be top ten