OK, there might be a few, but in many instances, when Government sets out to solve a problem, it often makes the problem worse. Take for example Lyndon Johnson's Great Society and "War on Poverty" of the 1960's. In 1959, the poverty rate was about 22%. It fell consecutively every year until in bottomed out at slightly below 9% in 1973. Since then, the poverty rate has pretty much remained in the 11-15% range.
Or take for example the Department of Education (whose estimated 2011 budget is $71 billion) that was created in 1979 during the Carter Administration. Part of its mission is "student achievement". Yet since then, while inflation adjusted education spending has skyrocketed, reading and math rest test scores have pretty much remained steady. This list of unsuccessful government programs goes on and on (ex. Cash for Clunkers, the various stimulus programs).