Here's a neat Google Video from Uman, Ukraine, on the eve of Rosh Hashana , where some 35,000 Hasidic Jews from around the world gathered to celebrate the High Holiday - the Jewish New Year 5767.
It's an hour of footage of mostly people milling around and of the crowd praying and chanting. However, , if you don't understand Hebrew or Yiddish (not sure which language it is) then you won't likely want to sit through the whole hour, but do scroll through it and take in a minute or two here and there. It will give you a real feel for the Hassidic Jewish sect, particularly the Breslov branch. Quite neat.
As well, there are a couple of great klezmer tunes opening and closing the video.