Check a video file (music doesn't tend to be rated as often) with Bitzi before download. If the file's been rated, you'll see other users' opinions of it
How to use Bitzi

Check the file size too...very roughly, a full length movie's 600-700 MB (some are larger, some a bit smaller). Preview the file after about 10% download to check that it looks ok.

Movie download tips
How to find music(this has tips for video also)