Thanks to everyone for the suggestions!
I'm definitely leaning towards the male African house snakes, Kenyan sand boas, or the hognoses. I've been looking at the house snakes ever since I decided to purchase my first reptile; I just love their color and disposition. I know a fair amount about hognoses, but I'd definitely need to do some research about all three and the differences betwixt them.
I'd thought about geckos, but I'm not sure if I'm a gecko person - keeping live bugs in my house seems terrible. But I think I should give them a chance sometime!
I've had bettas, but I got them from a big box pet store and followed their instruction to keep them in a tiny tank thinking that's all they needed. Needless to say, they lived a short, unfortunate life because I didn't do my part. I owe a LOT to the species so I think owning another betta CORRECTLY would be a good experience!