Pittsburgh, Pa.

Pittsburgh tops the small list of rust-belt cities that have cleaned up their acts, and it now ranks as a great place to live. One big change has been a dramatic drop in population - from 680,000 in 1950 to just over 300,000 today - that has transformed a once large industrial city into a smaller financial/high tech/health-care based economy.

Best of all, it is also a remarkably affordable city to live in. The median home sale price was $112,000 in August 2011, which is unusual for a city with top-notch hospitals and more than a dozen universities, art schools, and institutes.

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