"Again, we are talking about the MAN, not the various religions and the crap done in his name."
...I beg to differ. The title of this thread asks for positive influence. If people have been influenced to do negative things because of someone, than that counts against their 'positiveness'. Also, the spread of Christianity should fall largely on Paul's shoulders, thereby diminishing Jesus' influence substantially. I suppose many Christians on this site would argue that Jesus guided the work, but even if we agree to this, he did so from heaven, and thus I think should be excluded from a question that is discussing humans only.
(Because, I mean, if we're not talking humans, then I vote for the first self-replicating molecule as the most positive influential person.)