TL;DR: Internet usage was shutting down my entire cable box (Modem interfering with reciever somehow).
Ok, so basically my internet provider (Hickorytech provides DSL, Internet, and land-line phone) came and split the internet signal out of the DSL box and gave us (what looks to be) an old, used modem. Problem is, we basically have the exact same problem. Only difference is it doesn't shut down our TV also, just the modem. What happens is I'll attempt to download something, say an update for World of Warcraft. It will run fine for a random amount of time (sometimes less than a minute, sometimes 30 minutes), and then the modem will just lose internet connection, causing me to reset it. So what are some troubleshooting things I can go through that would help me figure out why this is happening? Because It's getting pretty damn annoying having to reset this thing over and over, while not getting anything downloaded.
Does the router/modem have DDOS (denial of service attack) protection -- try turning that off.
MTU -- the fact that crashes happen with big downloads may be a clue. Default MTU is 1500 -- try repeatedly lowering that figure by increments of 100 and testing. If that helps, fine tune by restoring 1500 and lowering by increments of 10.
Download TCPOptimizer or a similar program which will guide you on MTU settings.