I met Chris Johnstone whilst he was still lecturing at Bristol University. A softly spoken doctor with a huge experience that you can rely on. Easily understood, and simple graphics, followed by questions.
A great American resource whose focus is obvious from the name!
Mihaly Csikszentmihalyi is a bit dry but he gently shows the outcome of his investigations into happiness, career choices and what it means to be in a flow state or as sports people would say, in the zone.