This script places a ratings bar beneath video thumbnails and it indicates the enthusiasm viewers have for videos with an additional blue bar. This blue "Power Meter" is based on the ratio of 'Likes' and total views. In other words, it gives you an idea of how often people have hit the 'Like' button instead doing nothing or hitting 'Dislike'. Even a list of videos that all have 100% 'Likes' will have different Power Meter scores, pointing out the cream of the crop for you.
YouTube has been experimenting with the layout of their site lately and it's been breaking the functionality for many UserScripts, including this one. There doesn't seem to be any actual advantages to what they're doing, it's just an over-simplified and non-intuitive interface. If your browser has been 'volunteered' to take part in their test and you'd rather opt out of it so you can use your favorite UserScripts again, then follow these steps to get things back to normal:
1) On YouTube, click your profile icon in the top right corner.
2) At the bottom of the menu that appears, click "Restore Old YouTube".
When YouTube finally figures out what their final layout is, then I can make whatever changes I need so the script works on it. But I'm not going to go through making this script compatible with two layouts simultaneously, possibly introducing bugs, and having to manage both at the same time.
If you want to customize the thickness of the bar, the colors, the animations, or put the bar above the thumbnails, check out this UserStyle:
If you want detailed information about the ratings or want a better look at the ratings bar, hover over the thumbnail. The blue number is the Power Meter score (out of 100, but nothing gets 100). This is followed by the number of likes and dislikes in green and red.
This is a not-too-common case when the Power Meter is larger than the green 'Likes' bar. This can happen when the subject of a video is controversial and people are spamming 'Dislike' as a response to the controversy rather than the objective quality of the video itself. The Power Meter acts as a filter in these cases, helping you find the best videos about unpopular subjects.
The Power Meter needs an accurate view count to work. If YouTube can't make sense of the view count YouTube provides (more votes than views), then the bar will have green/yellow stripes and say "View Count Error".
In case you load a YouTube page and the ratings don't show up immediately, just scroll down the page. Whenever you scroll down or up, the script will re-evaluate the situation and try to get missing information from YouTube and display it for you as soon as it gets it.
I'm not asking for donations for this script. This is something I made for myself and have decided to make available to you because I think you may enjoy it. If you find it useful, then please consider giving the script a positive rating.