I favor PDFs because they are in form of self contained concentrated knowledge.<p>I can save them, print them, read them on e-book and they play nice and they do not have unnecessary elements like menus or side panels or what ever.<p>The same can not be said about a web page. If nice printing option is not provided then it is normally near impossible to print correctly, if I save them, it is not sure that they would display correctly years later, if I do not save them, I could not be sure I could actually access the information years later.