"If the movie trailer looks awesome, the movie is gonna suck!"
maybe you won't realize it but i did some research on it and so far, i was right.
just see what happens to movies like Prince of Persia, Clash of the Titans, Percy Jacksons and the Lightning Thief, Legion and Ironman 2. What a shame...
But if the movie trailer is too short, doesn't look good or it doesn't tells a anything clear, the movie will turn out OK and pleasant to watch. Just look at movies like Book of Eli, Kick-Ass, Predators, and The A-Team.
As a conclusion, watch the movie trailers first before you waste 2 hours of your life in disappointment.