People overlook a lot of midwestern cities that are great.
For example, Kansas City is a hidden gem. Very low cost of living, best BBQ in the world with any other type of ethnic food you could imagine as well, multiple medical schools, friendly midwestern people, lots of young people, safe urban center, etc. I would put it well above the more popular midwestern cities of St. Louis (dump), Chicago (expensive and crowded), and Cincinnati (area around university is frankly unacceptable), which made the lists above.
Nicer college towns can also be great: Charlottesville, Chapel Hill, Ann Arbor, etc.
I would also add Charleston, SC on the list. Awesome place to be in your mid 20s.
NYC/Boston/SF/Philly/LA are so overrated and not worth the pricetag IMO. You can visit them for vacation and conferences. Day-to-day? Forget about it.