Naked Economics is the most human-friendly pop-econ book I've read. For a reader who isn't familiar with utilitarian frameworks or cost-benefit analysis, it's a more gentle opposition-softener.

It's also less likely to leave a reader thinking "economics says we should do away with all governance". This makes it more palatable to left-leaning readers and less confirmation-bias-y to existing free-marketeers. When you're at a dinner party, it's easy to spot people who've read a single pop-economics book.