All types of snakes have their pros and cons...personally I'd recommend a cornsnake, milksnake, or kingsnake for the first time snake keeper. Like Shelby explained Ball husbandry is a bit more involved, and at times can be down right frustrating.

I'd stick away from the redtail right now unless you are prepared for a snake that hits a girthy 6 foot minimum. Its definitely alot of snake to handle, feed, and house. But on the plus side, if frequently worked with, and kept on a consistent schedule they can be puppydog tame and will hardly ever refuse a meal.

Ratsnakes (corns,milks, kings) are great snakes, "tame" very easily, feed well, and are very low maintenance living in much smaller enclosures, and they come in a huge variety of morphs.

Ball Pythons are great snakes as well, but you definitely need to do a bit of research before you jump into a purchase. Like any snake however they all have their individual personalities and limitations, so you'll find some that are quite tame, and some will always lunge and strike.

With all that said, do yourself a bit of research, and if possible attend a reptile show in your area so you can see several different types of snakes. Research, research, research, buy the best equipment for the specific snake, and then find a reputable source (LLLreptile ) to purchase your snake. Find one that suits your lifestyle and that you wouldn't mind keeping for anywhere from 10+ years.

Good luck with your decision!