I don't have much experience with the I-90 cities, so I really can't rank them. What I can do, though, is provide you all a nifty little chart illustrating how many metropolitan areas of at least 1,000,000 population each (two-digit) Interstate passes through:
11 - I-95 (Miami, Jacksonville, Raleigh, Richmond, Washington DC, Baltimore, Philadelphia, New York, Hartford, Providence, Boston)
8 - I-70 (Denver, Kansas City, St. Louis, Indianapolis, Columbus, Pittsburgh, Washington DC, Baltimore)
7 - I-10 (Los Angeles, Riverside/San Bernardino, Phoenix, San Antonio, Houston, New Orleans, Jacksonville)
6 - I-35 (San Antonio, Austin, Dallas/Fort Worth, Oklahoma City, Kansas City, Minneapolis/St. Paul)
6 - I-80 (San Francisco, Sacramento, Salt Lake City, Chicago, Cleveland, New York)
6 - I-90 (Seattle, Chicago, Cleveland, Buffalo, Rochester, Boston)
5 - I-5 (San Diego, Los Angeles, Sacramento, Portland, Seattle)
5 - I-40 (Riverside/San Bernardino, Oklahoma City, Memphis, Nashville, Raleigh)
5 - I-65 (Birmingham, Nashville, Louisville, Indianapolis, Chicago)
5 - I-75 (Miami, Tampa, Atlanta, Cincinnati, Detroit)
4 - I-15 (San Diego, Riverside/San Bernardino, Las Vegas, Salt Lake City)
4 - I-55 (New Orleans, Memphis, St. Louis, Chicago)
4 - I-64 (St. Louis, Louisville, Richmond, Virginia Beach/Norfolk)
4 - I-71 (Louisville, Cincinnati, Columbus, Cleveland)
4 - I-85 (Atlanta, Charlotte, Raleigh, Richmond)
4 - I-94 (Minneapolis/St. Paul, Milwaukee, Chicago, Detroit)
3 - I-20 (Dallas/Fort Worth, Birmingham, Atlanta)
3 - I-69 (Memphis, Indianapolis, Detroit)
3 - I-76 (Denver, Pittsburgh, Philadelphia)
3 - I-84 (Portland, New York, Hartford)
2 - I-4 (Tampa, Orlando)
2 - I-8 (San Diego, Phoenix)
2 - I-22 (Memphis, Birmingham)
2 - I-44 (Oklahoma City, St. Louis)
2 - I-45 (Houston, Dallas/Fort Worth)
2 - I-49 (New Orleans, Kansas City)
2 - I-59 (New Orleans, Birmingham)
2 - I-74 (Indianapolis, Cincinnati)
2 - I-77 (Charlotte, Cleveland)
1 - I-12 (New Orleans)
1 - I-17 (Phoenix)
1 - I-24 (Nashville)
1 - I-25 (Denver)
1 - I-29 (Kansas City)
1 - I-30 (Dallas/Fort Worth)
1 - I-37 (San Antonio)
1 - I-57 (Chicago)
1 - I-66 (Washington DC)
1 - I-78 (New York)
1 - I-79 (Pittsburgh)
1 - I-81 (Washington DC)
1 - I-83 (Baltimore)
1 - I-87 (New York)
1 - I-88 (Chicago)
1 - I-91 (Hartford)
1 - I-93 (Boston)
1 - I-96 (Detroit)
1 - I-97 (Baltimore)
0 - I-16
0 - I-19
0 - I-26
0 - I-27
0 - I-39
0 - I-68
0 - I-72
0 - I-73
0 - I-82
0 - I-86
0 - I-89
0 - I-99