Nudge is pretty easy reading from Thaler and Sunstein. Personally tough, I preferred his Misbehaving which goes into his history with the field. Way back when, I had a couple courses with Thaler when he was calling the field Behavioural Decision Theory.
Agreed - Misbehaving is a really interesting history of the development of the field, and the characters introduced along the way. I was also doing Thaler a dis-service, I find his writing to be far more page-turny than Kahneman or Sunstein.
