You people seem to be forgetting that Orochimaru's goal was to learn every jutsu in existence
something the Sharingan would have easily given him the ability to do.

Don't get too excited about Rin'negan most likely it is so highly regarded because it must be extremely rare.I mean up until Itachi the Sharingan and Byakugan were not only famous but also very common the latter of which still is.

While i may not be able to dispute the fact that it is the most powerful at the moment, i remind you that "POWER" especially in the Naruto world doesn't mean much. I mean its been said that the Byakugan is more powerful that Sharingan but i doubt a Hyuuga would stand a chance against an Uchiha simply because of the different abilities each doujutsu gives the user. Abilities>Power