First of all, HDD or SSD space is considered storage rather than memory. Without knowing how many games/apps you want to store I can only make generic suggestions. Most people seem to gravitate to 128GB SSDs. Personally, I use 256GB but then I can afford to. Either way, you should consider using the SSD in conjunction with a large HDD for bulk storage of large files and possibly games. Personally, I use an external HDD which allows me to shut it off when not in use.