I agree with the statements about Rosys. Kenyan Sand Boas are also a wonderful choice if you want a snake that requires no humidity and no attention. Problem with the fossorial snakes (fossorial = likes to be buried under substrate) is that they can get really stressed out momentarily when you are getting them out of their enclosures. Once they are in your hands, you cannot get those things to be aggressive at all.
But for the corn/bp debate, I have personal biases. I'm not a big fan of ball pythons. I think they look like slugs when they are full grown. Added to which, even captive bred BPs will sometimes go for months without feeding. I'm a huge corn enthusiast. I have 3 now, and I'm getting 10 more over the course of the next few months. They are, IMHO, the best starter snake, and even a great snake for experienced keepers. But yes, they are hyper, and they poop like crazy.
So, pick what works for you. I'm sure you'll find both species to be very rewarding.
- Ken LePage