I am particularly fond of the circular definitions where the meaning of a word is applied to itself, like:
• Nostalgia isn’t what it used to be.
• Reincarnation is making a comeback.
• Being superstitious is bad luck.
In similar vein:
• Don’t think just because you’re paranoid, they’re not out to get you.
• Have you noticed that all the people who favour birth control are already born?
• Meddle not in the affairs of witches, for…. ribbit? ribbit?
Some more paraprosdokians:
• He who laughs last thinks slowest.
• Before criticizing another man, first walk a mile in his shoes; then you’re a mile away and have his shoes.
• A bird in the hand makes it difficult to blow your nose.
• When the cat’s away you don’t need to clean the litter box.
• Everyone is entitled to my opinion.
• People only live happily ever after on a day to day basis.
• Sex is not the answer. Sex is the question. The answer is yes.
• Anybody can win, unless there happens to be a second entry.
• The best way to save face is to keep the lower part shut.
• My wife and I have a perfect understanding: I don’t try to run her life and I don’t try to run mine.
• Sticks and stones may break my bones, but whips and chains excite me.
• The secret of success is sincerity. Once you can fake that, you have it made.
• When it walks like a duck and it quacks like a duck, it probably should stay in the oven a while longer.
• The sooner you fall behind, the more time you’ll have to catch up.
• You can fool some of the people all of the time and all of the people some of the time, but you can never fool mom.
• Are you going to come quietly or do I have to put in earplugs?
Most of the above were sourced from Coast to Coast backpackers’ guide.