Good question. I confess your answers will differ from person to person. What resonates with one person won't do anything for another. I'll list some snakes roughly according to skill category, and hopefully something manageable will catch your interest.
Novice:
Gopher bull and pinesnakes are bascially the classic "snake" in appearance, rough scaled, varying earth colors, med-heavy bodied. 3-7 ft depending on species. Can't exactly stare through someone, but are generally good tempered and have marvelous physical strength.
Some american rat snake morphs. Not all that intense, but high on the "neat" factor. For example, a leucistic black rat snake is a pure white snake with the potential of reaching 8 ft or so.
Garter snakes. Don't laugh too hard.
Elegant, graceful, alert, and fast enough to teleport across the cage if they feel the need. If you come across the Aug 05 issue of Reptiles, check out the CA red sided garter photo on page 24. Stunning.
Basic intermediate
Carpet pythons, especially Jungle Carpet Python. The JCP reaches 6 feet give or take, and if from a good line, matures to a lovely black and yellow contrasting pattern. Homicidal maniacs when babies, but most grow out of it to be ok for handling. Deliberate, calm powerful movers. Even just lurking on a high shelf they're awesome. Humidity/caging requirements.
Green Tree Python, in the same family (Morelia) as the JCP. Scary looking face, can accept handling in the daytime. In the night, they expect food. Beautiful animals, and good at lurking. Humidity/caging requirements. Snakehook is friend.
Advanced Intermediate: capable of doing damage.
Indigo snakes, the largest snake native to North America. Intelligent for a snake, top of foodchain and knows it, beautiful, alarmingly powerful and generally docile with humans. Regretably endangered in their native habitat, difficult to captive breed, big waiting list and maybe as much as 1K for a cb youngster. Illegal in some states due to endangered status and I've heard they pack one hell of a bite. Still very, very awesome.
Vietnamese blue beauty snake, Gorgeous denim blue with black mesh pattern and black marks across eyes. Grows 8-10 feet. Fast and active. Can be highstrung and skittish.
Amethystine python, I handled a 7 ft youngster who was unusually docile once and I'm still trying to pick my jaw off the floor. Most intense snake I've ever encountered. Light brown/tan colors with purple/blue iridescence. Very, very, powerful animal. Poise like a dragon. One of the five largest constrictors. Has been recorded at 28 ft? (I think) but some localities don't surpass 10 feet. In Morelia family same as GTP and JCP. I think I'm biased. Varying attitude towards handling, depending on prior experience etc. Can be nasty! Slender animal.
Hope this helps with what's out there. I highly recommend meeting a few of whatever species interests you. Sorry if I missed anyone's favorite. Please pitch in guys.
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0.1 chickens (Condor)
0.2 dog mutts (half ownership, only mine when they misbehave, Lucy & Amy)
0.1 Halflinger horse (Crissy)
0.1 Normal phase California Kingsnake (Sophia)
1.1 parents
Still searching for 1.0 WC human