Well that depends on the size of the SSD a 120GB can take a fair bit in fact I run both laptops and two desktops with that size and admittedly I don't game and do stuff like that and I don't come close to using it up.
Pictures and music I save to the spinners. I have a 256GB SSD in my Ivy Bridge and really that is overkill.
So unless you have a SSD of around 10GB then I don't see why you are worrying about filling it up the OS is only about 5GB tops throw in some security and you would be miles ahead still with that capacity.