Larger (D1 level) US campuses I have visited. I am a chemistry professor so I get invited to give research talks / seminars often.
IU
Purdue
Northwestern
Ohio State
Pittsburgh
Cornell
Dartmouth
Columbia
Yale
Boston College
Boston University
Virginia
UNC
Georgia Tech
Emory
Florida
Florida State
Minnesota
Wisconsin
Kansas
UC Berkeley
UCLA
UC San Diego
BYU
UT Austin
UT San Antonio
Baylor
Rice
Maybe I am missing some.
The most beautiful campuses will depend on when you go (ex. Bloomington or Dartmouth in the fall). In general though, in terms of buildings, walkability, layout, nature, housing, etc I think the prettiest are Cornell, IU, Dartmouth, Virginia, UNC (in no particular order)
Then in terms of what the city has to offer, I guess it's up to what you want. Plays, music, bars, restaurants? Schools in cities with good public transport also have some appeal to me (Boston College, for example).
I may be a bit biased, as an IU grad, but IU always gets a mention in rundowns of most beautiful campuses.
I omitted small schools, since it's not relevant to D1 recruiting, but some of them are very scenic & compact (Wabash College, for example, my undergrad alma mater).
