I use a userscript called YousableTubeFix. It can be downloaded here: http://userscripts.org/scripts/show/57201
(You can also find versions for Firefox and Opera)
Using this simple script you can totally transform the way you use YouTube. It’s as if you started using a non-buggy version of YouTube, the way it should have been all along.
Here’s are some pretty cool features this extension brings to the table.
Video downloads.
Yes, you can easily download any YouTube video with a click of a button. It doesn’t take you to a “downloader” website or anything, it just starts downloading. It’s magic! (But really, it’s Javascript)
Configuration for default video quality.
Are you stuck on a slow connection at work? Or just want to load the video as quickly as possible? Sometimes, I suffer from both and having to switch to 240 quality every time I watch a video is a pain. Not anymore with this handy configuration. Just click the configuration button below any video page, and select your default quality setting. Every video from here on out will carry that video setting.
Video Window size.
Have a big monitor? Just choose a huge window size and every video will use that setting.
This script will change your life! If you love watching videos from /r/videos or you just like following the latest YouTube channels, this will definitely help you have a smooth experience.