I am going to have a couple of different lists for you, then you post your response to these. I will help you start with a few of my personal answers in bold & italics.
1. Movies that the trailer (preview) was better than the actual movie. (In other words, you were lead to believe that this movie was going to be great by look of the trailer, but you were dissappointed).
- Chronicles of Narnia
- Hot Fuzz
- Reservoir Dogs
- The Goonies (surprising amount of people I have talked to lately have not seen this)
- Star Wars (Empire Strikes)
- Evil Dead 2
- Mad Max 2 aka The Road Warrior
- Godfather 2
- Snatch (how many didn't see this because of what they thought this movie was about?)
- Harold & Kumar go to White Castle
- What's Eating Gilbert Grape?
- The Shawshank Redemption
- I still know what you did last summer