Since law school is no longer en vogue, I've known a lot of guys from my fraternity that have received MBAs over the last few years. All of them went to programs ranked in the 6-20 range. Some used the degrees to switch industries, albeit they ended up getting positions that kids from top undergrad b-schools would get, but I thought it was a good use of money. The guys that went back to the same industry switched firms but ended up in positions that they could have attained with two more years of hard work and networking. As lavidaloca pointed out, the value in the degree is more apparent in the long run than the short run, but that is a much riskier prospect than it was 10-15 years ago.
If you're set on climbing the corporate ladder and/or looking to lateral into another industry, get a degree from a top 20- ideally top 15 program. If you have a business background and want to be an entrepreneur, you're better off reading a few great business books, networking within your industry/city, and figuring out how to fund your first couple of start-ups because nothing you learn in business school will make you less likely to fail on your first venture.
If you're set on climbing the corporate ladder and/or looking to lateral into another industry, get a degree from a top 20- ideally top 15 program. If you have a business background and want to be an entrepreneur, you're better off reading a few great business books, networking within your industry/city, and figuring out how to fund your first couple of start-ups because nothing you learn in business school will make you less likely to fail on your first venture.