For comparison purposes, it would be worth it to me to visit (assuming I'd never been, which is true for some of these): NYC, Boston, DC, Miami, Chicago, Dallas, San Francisco, New Orleans, Las Vegas, Nashville, Philly, Kansas City, Detroit, Honolulu, a number of smaller cities with interesting histories/native culture. If I didn't know anybody in the following cities then it probably wouldn't be worth it: Denver, Houston, Indianapolis, anything in Ohio, Seattle, Atlanta, Phoenix, Omaha, Pittsburg