When I was a child, Kind of Blue was the only jazz album in my parent's collection. I thought it WAS jazz. As a teenager (during my hard rock period) I scorned it; it was't contemporary enough. However, as an adult I've come to love the relaxed melodic sounds of Miles' trumpet and how it interacts with the piano, saxophones, bass, and drums of the other musicians.
In honor of the anniversary, enjoy this video: