When Choosing HDD & SSD, First to have computer run fast you need a SSD (solid state drive). at least for the operating system. So if you only want OS on SSD you need at least 60GB. The Corsair SSD are fast & high quality. Corsair Force  LS 60GB SSD   (60GB) & only around $45.00. Corsair Force LS 120 GB SSD  (120GB) & only around $69.00. up to you if moneys not a problem you can go bigger, but at least use SSD Just for your Operating System. You can use SSD's for all Storage on computer. if you have SSD for OS and then for all other Storage use HDD's. For HDD's the Seagate 2TB or bigger work good  Seagate 2TB Desktop HDD   (2TB) & only around $70-$85. Both SSD and HDD are HIGH Quality & tested for years, and is best prices. Browse Through pages below and read specs and comments, there are many different ssd's & hdd's.