I picked up two oddities on BluRay, neither movie you would expect much from the 'remastering'. They were "Life of Brian" and "Blazing Saddles". But, upon getting them, my God the images were incredible. Gone was all the fading, the tearing of images (particularly in Life of Brian were some scenes were near unwatchably bad in the last remaster).. etc.
These aren't movies where you would LOOK for such things, as they're hardly visual spectacles, but the difference was staggering. BluRay transfers aren't just about going to 'hi-def', but also about the new and restored masters, making a lot of these movies look pristine compared to how you're used to seeing them.