Is there anywhere I could download System Shock for free? If not, where's a good place to buy it. I'm a huge Bioshock fan and want to try out its predecessor. Thanks.

There's no place to download it for free legally, but it's easy enough to find on Amazon or Ebay. GoG has System Shock 2, but you'd probably want to play the first one first anyway.

You don't really have to play SS1 to get the gist of SS2, which is easily available on GoG if you want to pay for it. You'll probably have to mod SS1 for it to be playable. The control scheme is hellish and getting it to run on modern computers is a chore as well.