I don't know about you, but it seems to me that Hollywood is giving away way too much in the trailers that are released for its movies.
Case in point, check out this trailer for Pacific Rim:
I'm sure that you'll agree that one of the best scenes in the movie was when Gypsy Danger smacked the Kaiju with a ship - it showed not only the size of the Jaegers and the Kaiju's but also showcased awesome combat, aspects of the movie that were evident in the trailer, without the need of showing that specific scene with the ship. I feel that I would have enjoyed the movie much more if that scene had been held in reserve, don't you?
Next trailer, 'Oblivion':
The trailer is pretty straight forward - it tells us what Tom Cruise's character does, explains what happened to Earth - and then, !BAM! shows us that what we were led to believe that aliens were actually humans. Sure, the whole trip-to-the-alien-ship at the end of the movie was great, but I'm sure people would have enjoyed the movie more without the 'reveal' - perhaps, owing to Morgan Freeman's status as a legend in Hollywood, the film makers didn't have a choice and had to put him in the trailer.
In any case, those are my examples - I'm sure there are many more out there.
Which trailers have given away too much, in your opinion? And does Hollywood give away too much in trailers nowadays?