Looking for interesting data sets? Here's a list of more than 100 of the best stuff, from dolphin relationships to political campaign donations to death row prisoners.
I. Ma, T. Wong, and T. Sankar. GECCO '07: Proceedings of the 9th annual conference on
Genetic and evolutionary computation, 2, page 2262--2262. London, ACM Press, (7-11 July 2007)