With the exception of Georgetown and Duke, I have been on all of these campuses, and this is how I would group them in terms of coherent landscape and architectural design and cleanliness.
The best:
Rice University
Stanford University
Almost there:
Yale University - Yale had a beautiful campus, but the Bienecke Museum kept it from my top spot. If that building were on the other side of campus away from the main tour route, it would have joined the top three.
Princeton University - Another beautiful campus, but let down by average landscaping.
Harvard University - Harvard did not feel like a campus, but like an office park with an international airport terminal right in the middle. I liked the chairs in the quad when we visited.
Dartmouth College - Loved that they kept the same architectural themes for 200+ years of construction.
Massachusetts Institute of Technology - Yeah, the buildings didn’t match, except that most of them would look out of place anywhere else than MIT.
The middle bunch.
University of Notre Dame - Very nice but very generic.
Washington University in St. Louis - The fake lifestyle center in the freshman dorms dropped this down from a high spot. The campus was too spreadout as well, even if some of the older and newer buildings were charming.
Johns Hopkins University - Even more so than UChicago, Hopkins felt like an island. Well maintained through, even if the sidewalks were a bit much.
University of Pennsylvania - Given the poor state of downtown Philly, I was pleasantly surprised by Penn’s campus. The pedestrian walkway with the vintage buildings in the heart of campus was charming. The rest, not so much.
California Institute of Technology- CalTech’s campus was so small it seemed like a boarding school. I liked it though even though there is hardly any campus there.
The laggards:
Vanderbilt University - Very bland campus somewhat disappointing given Vandy’s reputation. Several state schools in the south have nicer campuses.
University of California-Berkeley - Great campus, let down by poor landscaping, mediocre maintenance and allowing vagrants on-site.
Columbia University - This felt like a fortress, but was not terribly well maintained compared to the other Ivy’s.
Brown University - Very nice campus, but it seemed dirty and not terribly well maintained.
Emory University - With the small size and elevation changes, this is a tough site to build on. Emory did not succeed.
Maybe familiarity breeds contempts, but I find the two Chicago area campuses disappointing so they get the next to last slots.
University of Chicago - UChicago is impressive when you see it from a distance, but up close it lacks any kind of architectural integrity, and the maintenance is spotty.
Northwestern University - With Lake Michigan frontage, NU has one of the best sites in the country for a college/university. Too bad they squandered it with a haphazard site design and no architectural continuity. At least it is clean.
The worst:
Cornell University - Cornell seemed like a sprawling state school with little or no planning, architectural continuity or diligent maintenance. An easy last place despite the natural beauty of the area.
Outside this list, Wellesley has a particularly pretty campus, and among public schools, Wisconsin-Madison is one of the best.