Even though the Rinnegan is powerful, I honestly think the Sharingan has more of a chance at winning because Itachi could do Tsukiyomi and other powerful Genjutsu with it.
Rinnegan hands down :| you can control all basic elements and create any shiz u want and with Sharingan, u can do what? percieve movements -_- wow. Remember, only a very few of Uchiha's can obtain Mangekyou :/ even then it doesnt match up cause not all MS's know tsukiyomi/Amaterasu/Susunoo. Only Itachi who gave it to sasuke
Rinnegan is original form of eye and Sharingan , bayakugan etc are the weaker version of it..!! so i don't think that sharingan or byakugan is able to beat Rinnegan....!!
O_O thats not the legend. There was no Byakugan or Sharingan when the Rinnegan was around >.> SO6P gave his 'eyes' to one of his sons and throughout the generations it manifested into Sharin/Byakugan