Book Trailers that Matter

All books matter. They bring joy, inspiration, knowledge and/or entertainment. But sometimes there are trailers that come along that matter in a way that makes you want to share it with the world.
Currently, I have three such videos I'd like to share.
One is a beautifully drawn children's book called Change Has Come which is an inspiration about the future of America and the election of Barack Obama.
The second is an author reading from a book called Crazy Love. I can't watch this without getting emotional and I wish I could share it with the world.
The third is not a COS made trailer, but we did the distribution for it. It is the story of a mother's journey raising her autistic child.

What is the best book community out there?

We want to know what YOU think!
GoodReads, a favorite of COS, is a wonderful community of readers, but there are so many it's hard to determine which one to invest your time in.
A great deal of Ning sites have sprung up with groups for general readers and then genre specific. Shelfari and even Amazon's community have a great following. But, which one is best?
We'd love to have your opinion!