The SSD/HHD combo will be faster. The SSHD is a middle option: it's cheaper than SSD/HHD, but faster than RAID HHD's for most uses. I'd suggest getting a >180GB SSD for your OS and games, leaving at least 40% of the drive empty for performance (before trimming), and use a HHD for storage. You probably don't need 250GB; one of my computers runs off a 120GB quite well, but I don't have a massive steam account or anything. You can just buy another HHD as needed later. If you're on a budget crunch, then obviously that's the limiting factor and you should get a SSHD.