Well, the stimulus for one. It was supposed to jump start the economy, but if failed. It was supposed to ensure unemployment didn't fall below 8%... it hasn't been below 8% since Obama has been president, so again, FAILED. Bailing out GM and Chrysler... was supposed to 'save' the industry, but Chrysler still filed bankruptcy, and GM is far from saved. Ford, who didn't take any bailout money, is doing fine, profits are up, things are looking good for them. Again, the Keynesian approach FAILED. Nationalized health care, was supposed to be the end-all be-all to our problems, and reduce the cost of health care while increasing availability, it hasn't done so thus far. What it did, was kill jobs.
I tell ya, it might be better for you to list out all the ideas Obama has had that worked! The list of failed ideas is pretty long.