Board Thread:Theories and Speculation/@comment-26545929-20150630030815/@comment-2013124-20150630041234

At first it was a stalemate. Jiraiya could beat Orochimaru because he had some heavy duty seals and barriers that simply ignore Orochimaru's immortality. But he loses to Tsunade because his big finishers required too much time to prepare. You can't dodge her that long without taking a clean punch. And all it takes it one. Orochimaru beats Tsunade because his skill with mind games lets him play on her fears, and he can take one or two of her blows head on. Plus her time limit means all he has to do is eat a few.

By the end of the series it was Orochimaru by a wide margin. Because He had all his immense normal powers that we saw. But now he finally had a body which could support Sage Mode and his personal use of Senjutsu.

Just my opinion.