Where? A town of 50,000 with 100 restaurants, many bars, and multiple theaters and festivals would be a highly desirable place to live for many, many people.
Any college town, because students don’t have cars and necessarily have to takes buses or bike or walk everywhere. Eg Berkeley, Ithaca, Cambridge and more
Not the original commenter, but as they mentioned "college town" I would offer up Evanston, IL (home of Northwestern University) as a good example. ~75k population according to Wikipedia, so a little bigger than the target, but lots to do within walking/biking range and you can take the L into Chicago if that's not enough.