“Absolute” critter prevention would require fencing that you could sell to the nearest maximum-security prison when you got tired of looking at it. But if you can life with keeping them out almost all of the time, here’s a checklist. It does not consider aesthetics, and while we’re on the subject, don’t forget that whatever you build is only as good as the gate.
Deer. The fence should be 8 feet high if the fence is vertical, 6 feet if it slopes outward at a 45-degree angle (they don’t like broad jumps). Neither fence needs to be solid; all you need is some kind of barrier (wires are the easiest and least expensive) running horizontally from post to post, at intervals no more than a foot apart. Electricity is optional, but recommended for the 5-foot level. Bait it with peanut butter so they get a warning shock that tells them to avoid the fence.
Rabbits. Galvanized 1-inch wire mesh fencing or chicken wire, at least 2 feet high and at least 10 inches under the ground (they’re good burrowers). No power needed.
Woodchucks. Galvanized 1-inch wire-mesh fencing, at least 2 feet high and at least 10 inches straight down, with an additional 8 inches bent forward underground, making an L-shape (with leg of the L on the garden side) — woodchucks make rabbits look like pikers in the burrowing department. No power needed.
All three. Start with galvanized 1-inch wire-mesh fencing, the 5-foot size. Bury the bottom 18 inches of fencing, as described under woodchucks. Above the fencing, string wire at 4 feet high, and then at 1-foot intervals up to 8 feet high. If you’re not worries about raccoons, you can string wire at 4 and 5 feet, then run a band of black plastic netting between the 5-foot wire and the one at the top. If you are worried about raccoons, electrify the 4-foot wires and bait them as above under deer.