Two I can think of right off are "Just when you thought it was safe to go back in the water" for Jaws, and "Houston, we have a problem." from Apollo 13.

I'm biased, as I think the Alien tagline is perfect, but there have been many great ones. Just like the movies themselves, the responses will depend upon ones tastes in movies. Some of my favorites include:

This Time, It's War. (Aliens) Would You Like to Play a Game? (War Games) A Long Time Ago in a Galaxy Far, Far Away... (Star Wars) An Adventure 65 Million Years in the Making (Jurassic Park) Trapped in time. Surrounded by evil. Low on gas (Army of Darkness)

Btw, on many of these the poster is half of the equation.

I am biased too as the tagline for Alien is just about as perfect as it gets but I do like the one for Jaws 2 as mentioned above. I think you are right about the poster too and maybe that could be an idea for another thread if someone hasn't already started it somewhere.

@Charles Dance said:

@CrazyIvanova said:

Two I can think of right off are "Just when you thought it was safe to go back in the water" for Jaws,

JAWS 2

Thank you, Charles, I stand corrected. Actually I sit corrected since that's much easier.

Oh yes, there will be blood- Saw II

Sorry Jack, Chucky's Back - Child's Play 2

From rags to riches... to rags ~ The Jerk