A wading staff is a third leg. You plant it on the riverbed, lean a little weight on it, and move one foot at a time while the staff holds you steady. On a slow sandy flat you will never miss one. On a freestone river with round, slimy rocks and current pushing at your knees, it is the cheapest bit of safety gear you can carry.
Almost every staff here folds. The sections are strung on a shock cord or a coated cable, so the staff snaps together in one shake when you need it and folds down to about a foot to ride in a belt holster when you don't. The real choices are the shaft (aluminum is cheaper and tougher against rocks; carbon is lighter), the tip (carbide bites into stone; a rubber foot is quieter; MOJO's Knot is built for mud) and the length. The Staff Type column in the table sorts them. Every rating and review count came off that product's own Amazon listing when we built this page. The stars belong to Amazon's buyers, and Tom has not waded with these staffs himself.
Some well-known staffs are missing. Fishpond and Orvis don't sell theirs through Amazon listings we could rank, and Folstaf, the old standard, is reported to have stopped making staffs. Simms does, and it is on the list, but read its note first: the Amazon price that day was far above what fly shops charge for the same staff.