I'd highly recommend a Rosy boa. They are one of my personal favorites, and match your description perfectly. :)
They are incredibly docile, one of the easiest snake species I’ve ever cared for, small, come in several different colors and localities, and all around are a wonderful (albeit often overlooked) snake. I've owned a few of them, so I’ll type out a short general care sheet; hopefully this will provide the information you’ll need should you consider one of these guys.
Temperament: They are very calm, slow-moving snakes. Generally quite docile, most are fine with handling, and they rarely, if ever, bite people. Mine have all been content to find a comfortable place on my hand or lap and just hang out, unlike Colubrids (like King snakes and Corn snakes), which always seem to have somewhere to go. ;)
Life expectancy: When properly cared for, a Rosy boa can live 20+ years in captivity.
Size: Males average 1.5-2.5 feet, females are generally 2.5-3 feet, some a tad larger, but rarely more then 3.5 feet.
Feeding: start babies on mice pinks, and build up to one large mouse per week for adults. The general rule of thumb is to feed a rodent about the same in diameter as the widest part of your snake’s body. They are generally quite enthusiastic feeders; I have never had one that was a reluctant eater.
Humidity: This is a really low humidity desert species. A small water dish is fine on the cool side of the tank, but misting is completely unnecessary for these guys.
Temperature: Mine have done best with a basking temperature in the high eighties, around 87-89 degrees, with an ambient (background) temperature of 77-80. This can be achieved by use of under-tank heating pads, incandescent heat bulbs, or ceramic heat emitters.
Cage size: a 20 gallon tank is ideal for a single adult, but a 10 gallon is adequate. Just make SURE the lid of the cage is very secure, as these guys are amazing escape artists.
Substrate: Mine have done best on eco-earth by zoo-med, as long as it is COMPLETELY dry before putting it in my snake's cage. Paper towels, aspen bedding, or even reptile sand (as long as you feed your snake in a separate container to prevent sand ingestion) also works very well.
Other good species of snake would be Kenyan Sand boas, Milk snakes, Ball pythons, Corn snakes, King snakes, and Childrens Pythons.
I hope this helps, and if you’d like any more information on the care and maintenance of this species or any of the other species I named (or would like to see pictures of my own snakes); please feel free to message me and I’d be more than happy to assist you. :)
Good luck!