NOTE: This is outdated!!!!!
Here’s the real most OP and best Diablo 3 class for Inferno 

Everyone wants to play the most overpowered classes in the beginning of new games. Who wants to be stuck with some broken class that takes more effort and time to advance. There hasn’t been much information regarding the scaling of classes throughout Diablo 3 difficulties (Normal, Nightmare, Hell, Inferno). The only content available on Beta is level 1-13 within one-third of the first act, (out of 4 acts) on the easiest difficulty, normal.