I love Supertramp. Another underrated group like them was Styx. Both groups IMO were right up there with Genesis but somehow never got the same critical acclaim. Tremendous lyricism and textural creativity. I have not listened to all of their albums, but Supertramp seems to have hit their peak when I discovered them in high school and I have at least three of their best albums:
Crime of the Century,
Crisis? What Crisis? and
Breakfast In America.
The waitress on that cover was an actual waitress from somewhere, but I forget where I read that.