Kiplinger’s has published their 2011 list of best value public colleges. While I am not generally a fan of college ranking sites I think there is some validity to sites that rank colleges based on financial aid issues.
However, cost alone is not the only issue. Pay attention to the 4 year graduation rate because if you have to pay for more than 4 years of college it will be more expensive in most cases than the college that graduates students in 4 years.
You should also pay close attention to the average debt at graduation to know what you are likely to have to repay.
Like many ranking systems, the best aspect of the Kiplinger list is the information that it provides to students and families. Use the ranking as a general guideline but pay attention to the actual information they give you. And remember, many private colleges can be just as affordable as public colleges for families with low or middle income.