Receiving a college diploma comes at a cost. Besides the hours of studying, students usually find themselves buried in a mountain of debt by the end of their education. So every year, Payscale calculates college tuition costs, graduation rates, and returns on investments to compile a list of the values of every college in the U.S. So which ones just are not making a passing grade? Here's the ranking of the colleges with the worst returns on investment -- apply wisely!