I've always hated pulling up YouTube videos due to the comments, related videos, and other junk that are crawling all over the pages for individual videos. Well I have just found the cure from (@cliotech aka Jennifer Dorman on Twitter).
The cure is QUIET TUBE. All you need to do is drag the Quiet Tube button into your bookmark toolbar and when you find a video on YouTube or other related site you just need to click the Quiet Tube button and the video plays alone in a separate window...no distractions!
Check it out: QUIET TUBE