YouTube design is in my opinion way too simple. That causes serious readibility issues, which are fixed in this small UserStyle which adds some gradients and fixes some margins.

Firefox 3.6+ is required cause I was too lazy to create image backgrounds, i used -moz-linear-gradient instead.

Update 23.04.2010
-Fixed YouTube logo problem caused by YouTube CSS Change. Please update your UserStyle to see the logo again.

Update 26.05.2010
-Fixed series name font size in video title.