He got us out of the economic turmoil that was the 70's. We went from inflation and a fuel crisis to one of the largest economic and technological booms ever.
His policies were instrumental in the end of the "cold war" and destroying eastern block communism and tearing down the Berlin wall.
He broke some federal programs and made state and local governments more responsible.
Worse thing: National debt went up....but it could be argued that is more to do with the democratic congress (that had been there 40 years or so at that point IIRC) and their lack of spending control. "Reaganomics" created 200,000+ jobs ( a great thing), but since Congress couldn't utilize self control with spending (a bad thing) debt increased.