I at once voted ATB, they are simply neat as heck. Feisty mind you, but are amazing to look at and -can- be handled, I suppose, if you do well by them and handle them alot so they get used to it.
Another option which you did not put down is a Green Tree Python- those just rock, I -love- them.
Granted, arboreal snakes are more of a "lookers" than being handled types of snakes but they definately answer your criteria for wanting something different.
There are many smaller boas you might like, like the sand boas for instance.
Milksnakes come to mind(unless you consider these as kignsnakes)
A leusistic Texas Ratsnake- that's one cool snake in my opinion.
Lots of cool choices!
good luck!