1) The ones which incite a Happy-plosion in your pants
Usually reserved for the summer flicks or films which come with a ton of fan-fare.
These trailers capture the complete essence of the movie in 2 minutes and change and it metaphorically shoots a liter full of adrenaline into your system making your pupils dilate an inch wider, your heart pump just that much faster and your saliva glands to go into overdrive. But you don't need any further convincing since you've already bought your tickets, like, two months ago. Simply put, these trailers are the celluloid version of ecstacy. You watch it and you can't help but get high and want more.
See: X-Men Origins: Wolverine, Harry Potter #6, Watchmen, Transformers 2: Revenge of the Fallen, films featuring Jason Statham.
2) The 'Been There, Done That' ones which attempt to promise you something more but is really the same thing wrapped up in different coloured paper
Usually encapsulates the bulk of these genre films: holiday movies, romantic comedies, horror movies, films by Michael Bay or the Judd Apatow clan and films which feature Will Ferrell.
South Park explained these kind of trailers best in this season 6 gem:
You basically go in to watch this movies because familiarity breeds security. Comparable to McDonald's, there will be no unexpected plot twists over here, just more of that magic juice you know and want.
See: Any movie with Matthew McConaughey - even more so if it also features Kate Hudson, or movies directed by Uwe Boll (in that you know it's going to create new levels of suck)
3) The rare ones that unexpectedly grab your attention and make you hunt it down at all cost
Usually reserved for the foreign flicks, most independent flicks, or commercial films that truly intrigue the movie-goer, which is very rare in this day and age.
Now this third section of trailers is a big reason why even the most jaded movie-goer, scarred by brainless action films and neanderthal comedies, continue to brave the hallowed halls of the cinema. These trailers are not like the first, where it condenses everything and shoves it all up in your face in flashing lights and cut-rate editing. With the former, you don't have a choice but to sit there wide-eyed and slack-jawed as the movie execs spoon feed you every last drop from the magic drug. With this kind of trailer instead, it's a slow-burning kindling where something about the trailer gets under your skin - be it the music, the actors, the plot, the presentation of it all - and it manifests with continued viewings until the passion bursts forth into full-blown yearning. You watch it not because the movie folks tell you you should, but because you just really want to.
See: Brick, Cloverfield, Shaun of the Dead, Sunshine, Stranger than Fiction, My Summer of Love, The Reader.
There's no better high in the movie world then when a film totally and irrevocably delivers every bit of awesomeness as promised in the trailer. Such viewing treats like 'Forgetting Sarah Marshall' or 'Crank' is made that much more awesome because even though you knew some parts were coming, there was more from where that came from. The good parts weren't solely contained in the trailer and there were hidden goodness in the film. You walk out of the theater thinking, "Oh yeah. Totally worth that 11 bucks I spent!"
On the other hand, some movies are so generic and terrible that watching that two and a half minutes of footage sixty times is actually better than sitting though the 120 minutes of film time. All that stuff you were cracking up over in the trailer are now being groaned about.You can't help but feel cheated and embittered after realizing that you were basically conned into going into this movie that sucked massive shuddering balls.
Wolverine and Watchmen, I'm looking at you. In fact I'll give Watchmen a pass, since I was never really as into it as I was with the former. But oh, Wolverine, how you shat over my psych-itude and rubbed it in the turgid waters of cheesiness and predictability. At long last you promised a perfectly cast Gambit, but delivered about 7 minutes of screen time. You turned my snarling, raging anti-hero into a love-sick puppy with retractable claws. Before any nuance of real emotion can be properly conveyed, messy inane CGI-effect destroyed the atmosphere. The remaining boner that was stifled in my pants from viewing the trailer slowly deflated as the movie progressed. Nay. My proverbial penis actually retracted inch-by-inch into my body at the unghastly sight of my Wolverine being annihilated. Not cool, dudes. Just not cool.