I haven't explore more contemporary classical composers these days. Since my focus is on piano, I like Samuel Barber, and I thought both Morton Gould and William Bolcom wrote very interesting pieces for piano for the Van Cliburn Competition. Prokofiev and Rachmaninoff are some of my favorites. I know that they are older than John William, but they are still 20th century composers.
For movie sound tracks, my fovorite is Cinema Paradiso.