I've driven through Los Angeles, NYC, large portions of Ohio, Atlanta, Miami, Phoenix, and Washington DC, so I have experience with literally almost half the choices on your list and I can confidently say that Orlando beats them all, no contest. NYC is the only place on the list nearly as nervewracking to drive in IMO, but that is not because the drivers are unskilled its because there is so much going on, roads are frequently closed, and looking around finding a place to park magnifies the effect.
In Orlando I'd estimate I put about 750 "sidewalk miles" a year on my Ford Escort where I'd take it offroads a bit to get around all the idiots blocking the traffic.
BTW I am NOT referrring to the tourists going to Disney, they are much better than the average driver there. Anyways, Disney area would be Kissimmee.
I don't understand why Phoenix is on this list, the driving there is pretty good.... also, while Atlanta drivers may completely ignore speed limits, IMO this is a good thing. I assume this is the main complaint of those who dislike Atlanta drivers?
I would say the majority of the southeastern U.S. has far worse drivers than any city currently on your list, but its less hectic than some of the choices. Ohio drivers are pretty bad, but Miami drivers are worse, and so is the southeast in general. Orlando drivers are much worse.