Thanks to the wonder that is Tumblr, my attention was recently brought to the amazing film The Celluloid Closet. A documentary based off the book by Vito Russo, it analyzes the portrayal of gay characters throughout the evolution of film. (And it is pretty much just gay characters, not LGBT - there's maybe one ambiguously bisexual character, and no trans* people.)
I thought it sounded interesting, and I was not disappointed. A thoughtful look at many different kinds of films that all have their own problems or advantages. It's incredibly disheartening for the first half or so, of course - but don't worry, there's always a happy ending.
What I like about this documentary is the truthful commentary that comes along with presenting certain clips. I found myself agreeing with most of the things that were being said - for example, that gay audiences are so used to looking for tiny crumbs in media that we'll watch a terrible movie just for the possibility that a character might be gay.
This also put quite a few movies on my to-watch list. I can't believe I'd never heard of some of these. Overall, it's an incredible film, and I'm very glad I saw it. Why don't you take a look too?