Indeed, they're short-lived for me as well, added it to my comment. As per Sturgeon's law, most 'self-help' books are not very good, but just about any are a good refresher of some of the basics - like Focus on the goal or Make goals measurable, and track the progress etc.

In daily use, probably Getting things done has been the most influential for me - maybe because it's mostly about a number of useful techniques, rather than thinking too much about them.