You can (and IMO should) disable youtube suggestions based on your past browsing. You can also have it only store 3 months worth of tracking (in case you ever turn the suggestions back on).
It definitely lowers the quality of the suggestions... but that's kind of the point.
I take it one step farther and only watch YouTube in a private session and don't log in. When the recommendations get strange, I close the window and open a new one.
It definitely lowers the quality of the suggestions... but that's kind of the point.