Which blu in your collection represents biggest visual upgrade over same film on dvd?

[intbal]

My dad only has a dvd player and didn't understand that there's a different format with much better quality. So I wanted to make a presentation for him to show how much better blu-rays can be over DVDs. Unfortunately, in going through my library, I couldn't find many examples where the difference was dramatic (and noticeable for an Octogenarian's eyes). The biggest visual upgrade from dvd to blu-ray in my collection was X-Men:The Last Stand. However, I think that's only because the dvd of that was so terrible (the blu-ray is really pretty mediocre by itself).

So I'd like to hear from others. Which movies do you have where a "decent" dvd is put to shame by a great blu-ray?