…more recently I stumbled across an even better one called DF YouTube (Distraction Free), which lets you choose to hide a lot more than just the comments. You can hide suggested videos, trending videos, and a lot of other elements that make up the YouTube experience.
Seeing that gave me an idea – why not do this for other sites? A lot of sites load extra content along the top and in sidebars, whose purpose is to keep you on the site longer and engaged more. It’s trivial to hide, say, the trends panel in Twitter, but there’s is absolutely zero impetus for them to add that option.