This is going off topic... but..

Orochimaru was the third Hokage's FIRST choice for Hokage. A Hokage is defined to be strongest ninja in the village, I think (correct me if I'm wrong).

He wanted to pick orochimaru over jiraiya, the 4th, tsunade, and the other jounins.

The ONLY reason orochimaru wasn't picked was because of he was killing his own people.

It should be pretty from that alone that Orochimaru was stronger than Jiraiya, Tsunade, the 4th.

If anyone has any difinitive evidence that the 4th was stronger than Orochimaru... lemme know.

Note: "he sealed the demon" doesn't count