Cloverfield
I think people forget how much mystery surrounded Cloverfield back in 2008. Shrouded in mystery, there was no way Cloverfield could have lived up to the hype it built. I still like the film a lot (and find many parts of it incredibly disturbing), but it could never beat the joy and terror I felt watching this initial teaser trailer. Also, I love the fact that they don’t actually reveal the name of the film. To my knowledge, hat’s not something that had ever been done before, and it really got people talking.