Both ball pythons and corn snakes are wonderful. One thing to think about is what your plans/expectations are WRT handling. In some ways it may be easier to get a BP to eventually be comfortable with being out and about a lot, just because they're more slow moving and once they aren't teeny tiny babies they're big enough to roam a normal room a bit without getting into too much trouble, if you keep half an eye on them. Corns are faster and skinnier, and as babies they are teeny tiny; so they really require much more of your immediate attention while they out, until they calm down. A BP is a bit easier as a TV or desk buddy.
The flip side though is that corn snakes can tolerate lower temps and humidity; depending on where you set your thermostat in your house, your TV room, office, or whatever could well be a temperature that would be fine for a corn snake to hang out in but pretty cold for a BP. It's more of a project to handle your snake if you have to crank up the heat and then wait for it to get warm first.