I've recently gotten interested in snakes in the Pituophis family: Bulls, Gophers, and and Pines. I'm actually checking into getting a bull... they can get pretty large---up to 6ft.---but they aren't too heavy-bodied.

Gophers and Pines stay a bit smaller and there are tons of different morphs and colors. And, speaking of colors, there's always Kings and Milks (*cough* *cough* Sinaloan milksnake).