Mine would be the Emerald tree boa. Just my opinion, but they are the most beautiful snake. I remember seeing one as a kid at the Atlanta zoo and was just fascinated. Always wanted one in my younger days but fortunately never got one. Their was no info for the common keeper, no one understood the conditions needed for them to thrive in captivity back then (internet was not around). But here is a snake that when very young is bright orange with white, then completely changes color to a deep green. Doesn't get any better than that.They are not a "holding" snake, but I'm good with that