If light weight is a concern I go with a tarp, ground cloth, and bivy sack. Properly pitched, a tarp can be as rain resistant as a tent, and actually better than some. In winter, of course, a sturdy four season tent is the ticket.
I usually choose a lighter weight tent when privacy is a concern. Snakes are not an issue in deciding between a tarp or a tent - I have never had an encounter with snakes in camp, ever. Mice and rodents, possibly carrying hanta virus and other nasty diseases, are likely to be more of a hazard, and I have gladly gone to a tent when they have been around in large numbers.
A lot of people like hammocks, usually for the comfort factor of getting off the ground. But what do you do when suitable trees are not in your camp? Unless it could be pitched as a tent, I wouldn't even consider a hammock. There apparently is little no weight savings in hammocks vs. tents.
My experience is in the western US - Arizona, New Mexico, California primarily. Things might well be different on the East Coast and elsewhere.
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Geezer in Chief