Do Trailers Give Away Too Much?

This is something that has been on my mind as of late.

"A good trailer is harder to make then a three minute short film"
- Peter Jackson

The thing I've been finding that trailers are giving far too much away and pretty much doing more damage to the film then good. the two genres that suffer the most from this are comedy's and action based films.

For example, if you saw the red brand trailer for Bruno then you saw about 80% of the gags in the film. which makes me think, is other 20% worth my $10? No. a film like Bruno humour is based on shock value and not knowing what he will do next. So bringing out a trailer that showed so much is a mistake and completely kills the re-view factor that helps the film to have a good box office.

With action films, the try to tell the basics of the story though quick edits and then try to end the trailer with "the money shot". The shot that cost the most and when you see it on the big screen it will blow you away, but most of the times it doesn't, the shot is already shown and the surprise factor of the shot is ruined and makes me wonder, why are filmmakers shooting themselves in the foot? Can the story itself sell the movie? and not some effect shot?

The first Star Wars prequel got the trailer right, it had a slow start then cut to fast edits and left the viewer deaf and blind by the time the films title appeared on screen. the drawback to this was that people thought that the film was going to be completely different from what they saw and kind of left a bitter taste in your mouth.

Here are some films that I feel gave too much away in their trailers:

• Pearl Harbour - that shot of the bomb dropping was amazing but when it happened in the film it just made me go meh, I had seen it, it hadn't changed so what was there for me to take away from it now?
• The Dark Knight - the only complaint in this trailer is the truck shot, yes it is awesome but i would have preferred to have been taken by surprise and caught off guard while in the cinema.
• Ballistic: Ecks vs. Sever - the trailer gives away the ending.
• Step Brothers - same faults as Bruno, just gave too much away.
• Independence Day - watch the trailer and you can pretty much skip the film
• Kingdom of Heaven - shows too many key shots from the siege, but I will admit that the Second International trailer that had the rock soundtrack is one of the best trailers ever made hands down, it's fast, loud and gets you excited for medieval combat.

So what films do you think got it right? Which ones were just poorly done?