I'm going to have to restart my latest character. I had finished up the College questline and was on my way back to Whiterun, when I came across this random fellow running away from some other random fellow. He told me to hold onto his sword, so I said "sure" and murdered the **** out of him. Then the other fellow came along and asked for his sword, which I kindly returned to him to make killing him more sporting. When I attacked him, it added a bounty to Whiterun. I killed him, and got the message saying the bounty was removed because all witnesses were dead. "Good," I thought, "now I'll just fast travel to Dragonsreach like I intended."
So I'm outside of Dragonsreach, the guards outside are fine, no worries, but when I go inside I'm immediately attacked by a guard. I'm wondering what the hell is going on, but I can't really find out with this nitwit attacking me, so he dies. Next I walk up the stairs inside Dragonsreach and every single NPC (children included) tries to kill me. Being the absolute genius I am, I ran outside, back inside, and then outside again. This overwrote all of my autosaves (I'm so good at this). I had quicksaved before I walked up the stairs, in case something bad happened, but it turns out all sorts of console commands were of no use. I had 0 bounty with Whiterun, 0 infamy, 0 everything, and yet they constantly tried to kill me. My last hard save on that character was about 7 hours previous (I use quick- and auto-saves frequently), and 5 or 6 levels lower (I was at 39 when I went to Dragonsreach).
So, unless I feel like re-doing the last 7 hours of play on that character I think I'll just start a new one. Mages level up too damned fast, anyway.