What I wanted to say is,
Both in 250GB and 500GB, you can fit many, many games and other programs w/o having to worry about space.
Its just that with 250GB, you'll need a HDD to story data like files, videos, music and stuff (Not games, there's enough space on SSD).
With 500GB, you might just eliminate any HDD as 500GB is plenty for both games and programs and music and videos and all such stuff, unless you're a movie buff.
And by your reply, I think you can just buy a 250GB SSD and forget even about HDD if you don't wish to store too much data (again, I don't mean games, I mean files/ videos/ music/ stuff). Or get a 500GB SSD and surely forget about any more storage drive