Wowzer, I have a couple of examples.
Well, here are some...
- Superman Returns. When I first saw this movie in the theater, damn, did I think that it sucked. I then bought it on DVD. Now, I absolutely love the film, and I hail it as one of the best superhero films of all-time.
- Ocean's Twelve. I never caught this in the theater. One of my friends said that this movie was terrible, also. I bought this film on DVD when it first came out, and man, I thought it was terrible, because it wasn't like the first one, at all. Only before I was about to see Ocean's Thirteen did I think about watching Twelve again. Maybe it's because I drastically matured as a movie goer/critic after summer 2006, but I couldn't believe why I (or many people) thought it was bad. The movie was a pretty good movie. It wasn't like the first or third, but it was different. I learned that I can't just judge a movie based on it's predecessor, but I have to judge it on what it is, all bias aside.