Most people want to upgrade their 500GB hard drive in the PS4 to something with some more space. I have personally done some research and found out the best option is the 2tb Seagate STEA2000400 hard drive, which comes in a case which you can pry open (unfortunately rendering warranty useless), and then place into the console and use the PS4 hard drive in this case for other tasks. You can read more information about this hard drive and its benefits on EuroGamer - plus installation information. Let me know if you use something else, but this is the one I fully intend to buy soon.