I voted corn for their personality. They're super laid back snakes and while there are lots of morphs I've yet to see one that strikes my fancy as much as a nice normal. Kings are fun snakes but generally take a bit more work to calm down. Garter snakes are fun mainly because of their diet and feeding options. Hognoses are probably the cutest snakes in the world but can be feisty little suckers at times. Texas rats can be hell on wheels or calm as kittens - varies greatly from snake to snake. I haven't worked with kenyans but they seem like neat snakes. Seeking your mom's stamp of approval I'd probably go with corn(placidity) or hognose(cuteness). Either snake is pretty good at winning people over. A tough decision to make, I hope you're happy with whatever new species you decide to work with.