Userscripts.org

Removes ads and unwanted sections (configurable), allows downloading and resizing videos, changes the default video quality, expands the description and the video size, can prevent autoplay and autobuffering, etc...

Removes the avatars from Youtube comments, resulting in less clutter.

Fixes some annoying stuff with the December 2012 Youtube layout: - Centers the page - Enlarges the Video Player, the comments list and the new Channel page - Automatically scrolls to the Video Player

Replaces an embedded video with a link to the video page.

Buffers the video without autoplaying and puts it in HD if the option is on

Watch videos from video sharing web sites without Flash Player. You can view the videos with a classic video plugin or with HTML5's video player. A download option is also available.

Download videos from video sharing web sites.

A cross-browser script that adds a button to download YouTube videos as MP4 and FLV files. This script downloads the videos directly from YouTube and it integrates with YouTube's interface.

Adds video titles, shows previews and embeds on click. Also supported: Vimeo, LiveLeak, WorldStarHipHop, Nicovideo

YouTube Center contains all kind of different useful functions which makes your visit on YouTube much more entertaining.

Links the Youtube logo to "subscriptions" instead of "what to watch".

Adds instant Lyrics to YouTube and Grooveshark in a flexible panel. Multiple sources and a manual search form ensure that most lyrics are found. Firefox, Chrome, Opera and Safari

Download any YouTube Video

PERFECT YOUTUBE LAYOUT. Auto scale video size acc window size to get largest video. Video allways visible even scrolling. All content moves on sidebar and it can be auto hide/show. See screenshots inside...

Shows ratings of related videos on Youtube.

View Source Code of any homepage

Loop any YouTube Video

With this Script you can Remove anything frame or other thinks on a Homepage.

This script tags every video links on a YouTube page so that they can be downloaded easily -- using the title as the filename. On the watch page, it also shows all the available video formats at the top of the page.

Makes Youtube's "Watch" page (video page) better with a variety of features and options including a right-side description, older video players, style improvements, and much more.

Hides Suggested Videos and other elements. Blocks sections of the youtube page.

Automatically "likes" videos from users you choose, or anybody.

Makes thumbnails cycle though the 3 previews. Additional feature to view all thumbnails on mouse hover, and move off to hide them.

A script to add an rss feed button to youtube videos.

AutoLike +PLUS Facebook (15/04/2013) Sumit Patel --- Much Faster now... Automatically Like/Unlike All Statuses or Comment. Automatically Poke and Confirm/Unconfirm All Requests. Automatically Add Friends, Automatically Follow, & Subscribe.

Auto Like Auto Pokes Auto Add Friends Auto like Post And Pics Status And Auto Add Friends Auto Poke AnyOne On Facebook + Speed

Bulk Delete Your Friends in Just A Few Clicks.

Facebook Invite All Friends (15/04/2013)

Hide All Your Offline Facebook Friends In Side Bar!

Add a facebook link to Google home page... Only For Firefox