The magazine said the 2013 list was the first to have two institutions outside the Ivy League at the top and the first to be headed by California schools.
They were followed by three Ivies: Princeton University, Yale and Columbia.
Swarthmore College in Pennsylvania was in sixth place, the United States Military Academy or West Point in seventh, Williams College in Williamstown, Mass., in ninth and the Massachusetts Institute of Technology, two subway stops away from Harvard Square, rounded out the Top 10.
Princeton, No. 1 in 2012, changed places with Stanford, while Williams dropped from second. The University of Chicago dropped from fourth to 14th, Yale moved up from fifth, Harvard moved down two places, West Point held steady, Columbia moved up from eighth, Pomona from ninth and Swarthmore from 10th.
For the sixth year, Forbes worked with the Center for College Affordability and Productivity in Washington to produce the list.
The magazine said its rankings focus not on how selective colleges are but on what students get from their education. Salaries of alumni were the biggest factor, at 37.5 percent, followed by student satisfaction, student debt, graduation rate and scholarships like the Rhodes won by students.
Forbes pointed out the top colleges are not cheap, with Columbia now costing $61,540 a year in high-priced New York. West Point cadets pay no tuition or room and board but commit to serve for five years in the Army after graduation.
The University of California, Berkeley was the highest ranked state institution in 22nd place, followed by the University of Virginia in 29th and the University of Michigan in 30th.