One of YouTube’s most requested features is to show the video ratings for videos along with related bar thumbnails. Google has its reasons for not implementing it yet, but you don’t have to wait. YTShowRating and YouTube Ratings Preview are two plugins that show you the dislike/like bar before opening the video.
YTShowRating displays rating information beneath the view count, and it works for any video in the Related sidebar. It doesn’t display ratings anywhere else, unlike YouTube Ratings Preview.
YouTube Ratings Preview displays the rating bar directly beneath the video thumbnail. However it has the advantage of displaying ratings in both the Subscription, Search and Related video area; it sets up under any video thumbnail, anywhere on YouTube.
Download either of them and add them to your browser below: