The default 360p resolution sucks. It takes forever for the video to change resolutions, if it does at all. The buffering sucks (it was fine until maybe a year ago). Hiding the "Hide Annotations" button that I use on almost every single video sucks. I still haven't found a way to browse categories from the main page. The new comment system sucks. The constant attempts to get me to use my real name are fucking annoying.
Literally the only thing Youtube has going for it is the amount of content. I guess it's not totally ugly anymore, but based on the way I use it, the usability has gotten worse with almost every single change. No other site I use has managed to do that.
(Yes, I'm on Chrome BTW)