Having an MBA can give you an edge in the cutthroat world of business—but only if you pick the right school.

The wrong school could be a critical waste of time and money.

For our fourth annual survey of the World's Best Business Schools, we asked hundreds of American professionals with experience hiring MBAs to determine the best business school in the world.

They came back with a loud and clear answer: Harvard University.

Harvard pushed last year's winner, Stanford, down to number 3. In addition to the usual top American schools, international institutions like Cambridge University (#8), Oxford University (#9), and the London School of Economics (#19) also placed in the top 20.

The majority of respondents said that skills and knowledge is the most important takeaway from business school (69%), while 22% said that a network of contacts was a valuable B-school bonus.

Note that we only asked American hiring professionals to weigh in, so these 42 business schools are best for getting you a job in the U.S.