Red tail boas are very sweet I have a pair of normals and just between the 2 of them are varying patterns and colors. Salmons are very nice, there are lots of varying degrees of color in them too. Besides the regular Columbians I think the Surinams are very pretty but they are more expensive. But with any of them you can't really predict their adult colors while they are babies, all of the normals start out with grey. And as with any snake, the babies can be a bit nippy when they aren't used to people. Just be sure you have at least a 75+ gal for them as an adult as they can get 10-12 ft (I don't really see too many males over 8 ft though)