For years dad bitched about not having access to the movies and tv shows that I had. He was getting hosed by the cable company forever. After much deliberation I was finally able to convince him to make the cost effective investment of an HTPC.
There is room for another 3.5 inch drive internally but I would have to re-arrange a lot of cables. I will probably just add a large external USB 3.0 drive around Christmas time.
Edit* Updated to correct secondary storage - 4TB Shitachi