And you know, now that I think about it, I remember two very different reasons for Orochimaru's becoming a missing-nin (although they both do have to do with Sarutobi). I remember his leaving because they caught him in the act of experimenting on villagers, but the anime last week said that he left because Sarutobi passed him over when he was choosing the fourth hokage. Is that a manga v. anime thing, or were there really two reasons given for it?

I'm a bit of a sucker for parent-child (whether literal or symbolic) interaction in fics, too. And the betrayal on both sides...! Now I sort of want to write Sarutobi-Orochimaru fic (but only if I feel I can do it justice).