Here's a thread wth a list of movies that will fill the screen
List of Fullscreen 16:9 1.66-1.85:1 Blu-rays (it's slightly outdated there are more). Or you can look at this website's movie database for movies in 1.66, 1.78, or 1.85 aspect ratios (those will fill your 1.78 shaped 16:9 screen)