For those of you that think YouTube video quality sucks, here's a way to semi-permanently enable videos to be played in a very high quality MP4 format with AAC audio.
It's even better than the "watch in high quality" link, and will work on any video even if the video doesn't have a high-quality link.I'm using this trick now, as my connection has become significantly faster for some reason.
Oh, and it only works in Firefox. 1. First, get the Redirector addon from addons.mozzila.org
(CLICK HERE)2. Use the addon to set a redirection with the following settings:
Include Pattern: http://www.youtube.com/watch\?v=([A-Z0-9._%+-]+)
Exclude Pattern: http://www.youtube.com/watch\?v=([A-Z0-9._%+-]+)&fmt=18
Redirect To: http://www.youtube.com/watch?v=$1&fmt=18
Pattern Type: Regular Expression
3. Browse to any YouTube video. Redirector will now automatically add the string "&fmt=18" to the end of any video URL, causing YouTube to play a very high quality version of each video you attempt to view. Please note that in some cases this may have adverse effects on the audio quality, though.