Please!
I love this script and YouTube is so much better with this, just please bring auto resize back.

This makes Youtube so much better, and I highly recommend it to everybody.

I've been using GM scripts for Youtube as long as I have used Youtube. I don't own a TV so Youtube is my main source of entertainment. Mainly to force quality, in my case low quality (240p and forced wait to buffer) half of the time when I live at my parents's place with poor connection out in the country (512kbit/s on a good day, down to ~100kbit/s or no connection at all, on a snowy winterday).

On the other hand when I live at home in my apartment in a big city with unlimited 100Mbit/s up/down through a plug in the wall. I change the setting to force high quality (usually 480p, but even 720p for art and music, I don't really notice any improvement beyond that).

This script works fine even with the latest Youtube layout remake.
It has everything you should expect from one of these all-in-one Youtube scripts, quality settings, flash quality settings, aspect adjustment, size adjustment, download functionality, "lights out" effect and an easy to use user interface for the settings.
Also a great plus are that the extra buttons are in the same style as youtube buttons, nothing looks out of place.

The only things I wish for right now with the script is an option to remove the "Guide" on the right hand side of the screen and a translation to Swedish, and I think I will start translating it soon. Not because many Swedish people don't understand English, but for uniformity, it looks better when Gnome is in Swedish, Firefox is in Swedish and Youtube itself is in Swedish. Same as with the buttons, when the buttons looks like "real" Youtube buttons it just looks nicer than if you add a new style. This Script melts in so well that you almost forget it's there, so I really feel like translating it might make it melt in just a little more.

Thank you for this great script I'm looking forwards to new versions.

Works like a charm, does what it says and even more.

I had several scripts before doing what this does alone.

I loved this but you have to rebuild it for the new youtube design (october 2012)

this is one of the best scripts for youtube and with a great UI .. GG

Has everything I would really need in a Youtube script with a very elegant interface.

Like most of us I've used several YouTube scripted managers, and I have to say 'YouTube Center' IMO is really the best, at this time.

Access to and navigation within options is excellent, the script is fast (I'd presume this means well coded), the script is reliable and the options are clear to understand (doesn't forget newbies!).

"A true facility for enhanced Youtube pleasure" would sound nice in an advertisement. Point is: it's true :)

Awesome script. I'd been looking for one that would do one thing. Make the large player default and set the video quality to its native resolution. And this does that, and more. It's nice to be able to download videos too. If you spend any amount of time on YouTube, I highly recommend this script. I only hope it can be updated to be compatible with HTML5 if/when YouTube decides to implement it.

Nice one Yeppha!
- Keep up the motherf*cking great work! :)