Disclaimer: I love economics more than is probably healthy or rational. Analysis of non-typical problems in an economic manner makes me all warm and fuzzy. I think I fell in love with economics in college because the way it establishes a framework for answering difficult questions with the proper logic and data analysis. So Freakanomics and SuperFreakanomics (best title ever, by the way) are so right up my alley that they could only appeal to me more if they had kittens on the cover.
So Freakanomics and SuperFreakanomics are pretty much the same deal. They apply economic-type analysis to problems that are not normally considered rationally. SuperFreakanomics has anecdotes that they just didn't get around to in the first book. I just hope they keep writing more!
One highlight for me was the section on prostitution. It described how pay for prostitutes has eroded over time, and why many American women choose to sell their bodies part time. Some make way more than I do.
SuperFreakanomics talks about the frontiers of modeling (the interesting kind, not the kind with weird clothes and skinny girls) where a bank used its database to predict which of the bank's customers were likely to be planning terrorist attacks.
Each chapter has different themes, questions and answers. It really makes you think about all kinds of stuff. SuperFreakanomics cites studies, describes interviews and looks at all this stuff from all kinds of angles.
I definitely recommend these books (I think the order in which they are read is unimportant) to anyone who reads. Superfreakanomics encourages the reader to let loose the rational side of her brain and apply critical thinking and the scientific method to whatever life throws at her!