Is 4gb of ram enough?

Hi apple fam, im considering getting a macbook pro. And i wanted the one with an optical drive so im going with the regular one. I was wondering would 4gb of ram be enough for me. I usually use my computer for music, social networking, youtube, netflix, hulu, playing diablo, streaming video games and watching streams, and skype. And thats about it. So what do you guys think? Think i should go and bite the bullet and upgrade it to 8gb of ram? Or is 4gb enough?