I used to own an Indigo wayyy back when I was a lil kid, until it some rat bastard stole it at an animal show I took it to, and it was illegalized to own them without a license.
I don't remember too well and my opinion may be a bit biased (you know how kids are, or your memories of childhood), but I used to love that snake. I remember that it was a huge snake and was much bigger than me (around 5-6 ft), but it was very calm and almost lethargic, allowed me to hold onto his head and pet him. However he was downright frightening when feeding time came around. We used to feed him rats and he'd do this twitching, curling up in an S, hissing business and struck and slammed the heck outa the dead rat, and occasionally, he'd over do it, and the rat's guts would kinda come out. Also he was very pretty, and I never got tired of just looking at the snake's scales almost shimmer in the light, almost put me in a trance.
From what I can deduce, they're expensive as hell to own now, and some people say they're nervous and flighty snakes, maybe I got lucky and got a laid back one.
But owning one would be like owning a lamborgini (and you'd better put insurance on it, and better not go showing it off since chance of getting it stolen is too much of a risk). But heck, I'd put that one down as my favorite snake, no other snake can match the drop-kick irridescence of an indigo along with a relatively high safety margin to the handler (I think, since I've only owned one, can't say too much about the rest).
Oh yeah, forgot to add, please avoid getting bit at all costs. Though they seldom bite if ever (washing those hands after handling rats helps), they can give one of the nastiest bites I've ever seen. Razor sharp teeth, and all that energy and fervor and thrashing they do.
-Lemur 6