Get
- Good antenna
- XBMC installed on your PC
- A good PC TV tuner card
- A robust hard drive (2-3 TB should be good)
Once done, you can install plug-ins for XMBC that provide you a TV guide. Identify what you want to record from your OTA antenna feed on that guide, and when it airs it will be saved & compressed to your hard drive for later viewing pleasure. XBMC also handles gathering meta-data for your TV series and displaying your media library back to you in a usable format for easy selecting.
The above solution is a legit, low-cost & legal one that I employ. Beyond an OTA antenna, there are also less than ethical/legal ways of sourcing your media, and then storing it within XBMC, but there are other forums for that.