Lipsey & Chrystal: Economics 12e
Econport is "a digital library for microeconomics education", supported by the Economic Science Lab at the University of Arizona. Econport offers a number of compelling resources, including useful discussions of consumer theory . However, the primary 'USP' of Econport is the support for economics experiments. You will need to register with Econport to be able to access the experiments, but once you have then you set up and run your own Generalized Axiom of Revealed Preference (GARP) experiment.