When Facebook’s Libby Leffler concluded that she wanted to apply to business school, she made one big decision: To apply to Harvard Business School and not to another famous school less than two miles away from Facebook’s headquarters in Menlo Park, Calif. Ultimately, she was drawn to the East Coast by the HBS alumni she met in her business dealings at Facebook and Google as well as the learning process in Harvard classrooms.

Leffler’s visit to the HBS campus, she explains, convinced her that the MBA experience at Harvard would not only be transformative. It would be, as she puts it, one of a kind. “Before ever applying to HBS, I made a personal decision that if I was going to go back to school and step out of my work at Facebook — which was challenging and hugely interesting in itself — I needed to be able to step into an environment that was fast-paced and unfamiliar,” says Leffler, who as senior manager of strategic partnerships at Facebook had worked closely with COO Sheryl Sandberg. “The case method requires you to learn new things in just this way. It demands preparation and synthesis of a large amount of (often incomplete) information to get to the heart of an issue very quickly and then engage in a productive dialogue with the people around you.”

The rich quality of the MBA experience which attracted Leffler to HBS is the reason why Harvard Business School was able to reclaim the title as having the world’s best MBA program in Poets&Quants‘ 2015 ranking of the top business schools. Nudging aside Stanford GSB, Harvard emerged the No. 1 program for the fifth time in six years in our composite ranking, evidence that an MBA from the school remains the quintessential credential in business.

HARVARD’S RESOURCES & REACH ARE SECOND TO NONE

No rival beats Harvard in the formidable resources it brings to the game: more superstar professors than any other school, the diversity of its course offerings, the stellar quality of its students, the size and scope of its campus, and the career achievements of its alumni spread all over the world. Hardly resting on its laurels, HBS has in recent years taken a lead over all rivals in leveraging technology to deliver business education, emphasizing entrepreneurship and innovation in its core curriculum, and providing well-planned global immersions for its MBA students. It also has the capacity to retain its lead, with a $3 billion endowment, three times the size of its nearest competitor Stanford. With three years left before the end of an unprecedented $1 billion capital campaign, HBS had already raised $861 million by last June.

Stanford, rocked by a leadership crisis and sex scandal that has made headlines all over the world, slipped to second place in the new P&Q ranking. More telling, perhaps, the gap between HBS and its perennial West Coast rival–as measured by the underlying index scores in the ranking–is the widest it has ever been since P&Q began ranking MBA programs in 2010. That is a surprising development because the rankings have yet to fully reflect the damage to Stanford’s reputation caused by the scandal which has left many alumni feeling disappointed and angry with the school and the university.

P&Q’s lineup of the best U.S. MBA programs, which combines the five most influential rankings and weighs each of them by the soundness of their methodologies, produces a more credible list of the best MBA programs. All so-called M7 business schools, the super elite group that comprise the Magnificent 7 MBA programs, are all solidly in the top seven. There’s No. 3 Chicago Booth, No. 4 Wharton, No. 5 Kellogg, No. 6 Columbia, and No. 7 MIT Sloan. Rounding out the Top Ten are No. 8 UC-Berkeley Haas, No. 9 Dartmouth Tuck, No. 10 Yale School of Management.

Getting into any top business school is as difficult as ever, especially at the more highly ranked schools. Some 9,686 applicants applied for one of the 937 seats in this year’s incoming class at Harvard. With an acceptance rate of just 11%, nearly nine out of every ten candidates were turned away. And the odds at Stanford were even steeper, with the school accepting only 7% of its applicants.

The degree’s appeal, moreover, has never been greater, especially at the most highly selective MBA programs. This year MBAs from the best schools have entertained all-time high offers in starting pay, with the Great Recession a distant memory. Graduates of both Harvard and Stanford business schools walked off campuses this year with median total compensation packages that exceeded $150,000 in salary, signing bonus, and other guarantee comp.

CORRECTION: The story has been updated to account for a correction in the rankings which puts Washington University’s Olin School at a rank of 23rd. We regret the error.