I'm a long-time TiVo user. I thought my wife would like DVR capabilities, but I didn't want to shell out for another monthly subscription. (My brother says these nickel and dime payments are the bane of modern existence, so he keeps them to a bare minimum--including watching only broadcast TV. But I digress).
My solution: purchasing a Panasonic Showstopper on Ebay. These units do not require a monthly subscription. They usually go for between $100 and $150. I upgraded the hard drive using an external USB hard drive case and this software, RTVPatch W2K GUI. I also downloaded an image file (Showstopper&replay30xximage3.02.zip) from www.replaytvupgrade.com/ This approach meant I didn't have to monkey around inside my computer.
In short order, I had a no-subscription DVR for about $200.