The winners of this year’s pseudo-Nobel Prize in Economics are Fama, Hansen and Shiller. Marginal Revolution has a good series on what Fama did, what Hansen did, and what Shiller did. Hansen’s work is the hardest to understand in that it is basically stats. Here are more explanations.
Shiller of course had a lot of commentary on the recent bubble and crash which you should read.
I have nothing useful to add that is not in these links.