Oh my goodness, has there ever been another film so beautiful, so influential as Blake Edwards's 1961 magnum opus Breakfast at Tiffany's? Nevermind how much it differed from Truman Capote's original novella about a call-girl and her bisexual writer friend -- this film was a true feat all on its own! Featuring the marvelous Audrey Hepburn as Holly, along with George Peppard, Patricia Neal, Mickey Rooney, and Buddy Ebsen, this film has remained a timeless classic. Why, you may be asking? A simple answer is that even if you weren't listening to the elegant dialogue or Mancini's beautiful "Moon River," this film would still take your breath away because Edwards really makes each shot of this film worthy of being a framed photograph. Its so stylistic in every way that you just feel immediately more sophisticated upon watching it (even if you are only in sweats and gorging on popcorn like I often do!)
Every girl I know has, during one point in her life or another, wanted to be Holly Golightly. No it wouldn't be enough to dress like her or adapt her fear of mean reds or love of Tiffany's -- they actually wanted to become this character. But eventually after a few weeks they would give up in vain. If you are one of these girls but are a little more determined to succeed, I recommend you checking out the blog Chic and Charming (if you haven't viewed it, I highly recommend it -- it's really wonderful), they posted a list that details everything in "Breakfast..." so that you can legitimately own all the same things Holly did, associate with the same folks, dine at the same places, even use the same brand of cake mascara. I myself dilligently took notes upon first viewing.

Chic and Charming's great list of How to Be Holly Golightly
http://www.chicandcharming.com/2008/01/how-to-be-like-holly-golightly.html

Also, I just thought I'd post this Wiki-how guide to being Holly. Its quite fun as well
http://www.wikihow.com/Be-Inspired-by-Holly-Golightly