Userscripts.org

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

Adds &fmt=18 to the url for high quality but not if any &fmt=x already exist and adds &fmt=18 to all the links

automatically pauses the video when you switch to a different tab or window, and automatically plays when you come back to it. optionally, pauses the video when scrolling.

Automatically scrolls to the vido on load

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.

Bypass YouTube's age verification requirement by playing age-restricted videos directly on the verification notice screen. ONLY allows watching, does not provide a comments page, etc.

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

Pops up a confirmation box before you leave a page so you don't accidentally leave a video you're watching

Allows you to use customizable seek times to skip intros on a series or anything you might need

Customize YouTube's Player Page

Skips the das captcha page on YouTube

Replaces YouTube Flash/HTML5 player with native plugin or plain HTML5 player.

Dim the Lights and watch your video in peace. Auto Dim lights setting (statusbar icon menu config). Works with Firefox, Chrome and Opera! Currently testing, Working well. Try it.

Changes javascript links into direct links

Adds a download button to every video on YouTube. Multilingual, Auto-Update & Multiformat supported! (Flv + high-quality Flv & Mp4!)

Add downloadable links in Youtube Page

Creates a download link for youtube videos with different resolutions. Optionally removes comments on video pages. Multilingual.

Get Download Links for Videos at YouTube

Removes video advertisements

Youtube Enhancer = Youtube catcher ( 9 formats ) + Youtube custumizer ( Like going to the movies ) + Youtube lyrics

Download Link + Quality Selector + Rollover Preview + Media Controller + Media Resizer + More...

Expands the full description of the youtube video being played by clicking 'more info' link on the top right panel on youtube, Showing you full description, category and tags.

Adds menu (bottom right) with download links for available video formats. Works with Javascript disabled (NoScript).

Make YouTube more like Google Video

Show youtube videos in high quality.

Select playback quality for YouTube videos automatically (720p by default), support both HTML5 and Flash player on all major browsers.

Automatically plays the best quality YouTube video format and removes ads, plus several optional features

Automatically plays the best quality YouTube video format and removes ads, plus several other optional features

Perfect package to enjoy HD videos in YouTube. Always watching or downloading the highest quality format ( 4K / HD 1080p / HD 720p / HQ FLV / MP4 iPod ). Add download icons in video list page.

The best YouTube script. I know it, and you know it.