Thinking Fast and Slow is a good book that is not at all a cheesy self-help pamphlet. It's a review of some of the more surprising findings of behavioral economics, and a discussion of how we should and shouldn't rely on heuristics in our decision making. It does suffer a little bit in that some of the topics have failed replication, and it could be about half as long as it actually is.

I suspect the entire category of self-help books could be described as "a good pamphlet stretched into a book"...