At this moment I have a 256 Gb SSD from samsung (830) I use this for my OS and most important programmas that I want to use fast such as steam including my better played games.
Than I have a 630 Gb WD green HDD That I scapped from my old pc which I use for downloads only
And I have a 1,5Tb WD green HDD that I bought when I assembled my new PC this is for mass storages including all my game files.