I'd go with Matthew Rabin.
He's a behavioral economist (in other words he incorporates psychology into economics) and writes interesting stuff.
here's a link to his homepage
here's a link to info on him on wikipedia
An easier option, which is also quite good would be to go for Daniel Kahneman and Amos Tversky. They are actually psychologists that won the nobel prize in economics for their work in behavioral economics, most notably in
prospect theory.
If you have any questions about the above, let me know.
Jared