These were REALLY REALLY hard to narrow down. I know I have more, but I think these always stay in my top 5.

Wings of Desire:


The Royal Tenenbaums:


It Happened One Night. I couldn't find a trailer, so here's a snip-it:


Breaking the Waves:


Eternal Sunshine of the Spotless Mind:


And I couldn't find a video for this one to upload, but you can watch the trailer here:

Flirting:
http://www.imdb.com/title/tt0101898/trailers-screenplay-E12392-310

And I know that was 6, but whatever.