Quotes / Trailers Always Spoil

"Shall I spend three-and-sixpence to purchase the book,
Which we all can pick up on the bookstall and look?
Well, it may appear strange, but I think I shall not,
For the back of the cover will tell you the plot."
Tom Servo: So they're all clones?
Crow T Robot: No, that was The Island's secret."
MST3K on the Transformers Trailer [1]

OK, so Jake is just this regular dude who has this thing for the very righteous babe, Allison. And the two of them meet this gnarly old magician named Zebediah, who actually happens to be this creature-person exiled from the underground world, only there's no way you're supposed to know that yet, OK?

Showing the Kraken in the Clash of the Titans trailer is like asking a girl out with your dick hanging out.

I don't think we can complain when trailers give away too much AND complain when a trailer shows stuff that's not in the final movie.
Watch The Mysterious Murderer. If you already saw it, don't spoil the ending. If you haven't seen it, you will never guess until the last moment that the mysterious murderer is Jack the Stranger
— The trailer of The Mysterious Murderer routine by Les Luthiers

James Voysover: Coming up, in "The Gift Shop Sketch": the end of "The Gift Shop Sketch"!
Shopkeeper: Eh?!
James Voysover: But first, the bit before the end!
Brain: That's perfect! It's like you've met my aunt.
Shopkeeper: Yes! She's my aunt, too!
Brain: Daddy!
James Voysover: And now, the end!
Shopkeeper: Eh?!

Jeremy: Why don't we just split up and cover more ground?
Voiceover: Seriously? That was the second plot twist!
Natalie: Yeah, I'll go with Tom.
Voiceover: ...And that was the third.
Jeremy: Of course you will.
Natalie: There's nothing going on between us!
Voiceover: Really? Well, since we're all sharing secrets, she kisses him later in the trailer. And then she dies.

"Cleveland? Who knew we would run into you, except everybody because Fox spoiled it in the promos?"
Peter Griffin, Family Guy, "The Splendid Source"

The thing with Leap Year is this - we saw it yesterday, although I actually really saw it several weeks ago when I saw the trailer. [...] And I made a note of it, that took us up to one hour and 17 minutes into the movie, which clocks in at just over 90. So the trailer left 12 minutes of the movie unknown. Blimey, I didn't expect the nuclear strike that happens in that last 12 minutes.

http://tvtropes.org/pmwiki/pmwiki.php/Quotes/TrailersAlwaysSpoil