You can get literally any TV series you desire via usenet. If you are heavy into sports, then you want satellite, but otherwise, just use binsearch.info, a usenet client, and $9 a month for a usenet account.
Or, if you are cheap/poor, then use bittorrent and a site like eztv.it or mininova. It's much slower for downloading, though, and more difficult to find what you want.
I use a Mac Mini on my TV with Plex software. It works great and has native support for the apple/harmony remote. Highly recommended.