15 Awesome Scenes From Trailers That Were Stupidly Cut From The Film
Honourable Mention - Any Pixar Movie
Pretty much every Pixar film (A Bug's Life and beyond) has had a short 60-120 second teaser trailer made up entirely of content not featured in the film. A microcosm of the feature, they capture the general tone of the film and the personalities of the characters without giving away anything substantial of the plot.
While many of these (Monsters, Inc., The Incredibles and Ratatouille particularly jump to mind) could easily have fit in the final film, they're standalone pieces (in the same way as the Terminator 2 or Back To The Future trailers) that were never intended to appear in the film, but are brilliant enough to warrant an honourable mention here.