Royal python ('Python regius'), also called 'ball python' in the States because of their habit of, when feeling threatened, curling up with their head buried in a heap of all their coils.

Captive-bred ones aren't bad for beginner snakes (the other recommended beginner snakes are kings and corns); they're sweet-tempered, though very shy. Known for going off their food for lengthy, irregular periods; this is really, especially bad with imports, aside from the ethical problems with importing them. (Habitat violation, and they tend to be brought over in very, very bad conditions.)

They're sacred in some parts of West Africa.

The Ball Python Manual is both cheap and a pretty good care overview. :)