YouTube needs to change its rating system as it is currently not doing the job it was intended for.
Firstly, its not clear what you are rating as one to five stars. Is it picture quality or content quality or whether you disagree with whats in the video? Users seem to use ratings for all of these purposes. Secondly, there is the problem of "votebotting", where automated scripts fire off one star ratings to a selected group of videos to reduce where they appear in Youtube's search reults. This seems to be most common by religious fundamentalists against the various atheist channels. Often these videos get many more votes than they actually get viewings which makes an illogical nonsense of the ratings system.
I want YouTube to make their ratings system more like Ebay's with specific one to five star ratings for picture quality, content and like/dislike or agree/disagree. This will stop the general confusion over what is being rated. If this is combined with captcha or a similar technology then it will prevent votebotting. I am not convinced that votebotting is that difficult to stop as I have written online applications which prevent multiple attacks for things like the testing of credit card numbers or blocking password slamming. I am no expert, so the people at Youtube should be able to come up with something much better than I could.
This way we can have a ratings system which adds to the accuracy of search on the site and makes it a level playing field that does not favour the dishonest.