I am not a gadget geek, but I should say that it depends on what are u going to use ur PC for. As for gaming only 8gb is pretty basic, as most of game requirements or reccomended spec say so., if the game require bigger ram, just follow it. And as the previous comments, the important part of RAM is not it's size but speed and compability.
and FYI, a bigger RAM do increase the performance on certains RAM relying programs, Video Editing programs are the simplest example. And perhaps also video recording and streaming purposes (I dont really know, just listened the winds and never actually did those 2)