When my Hughes DirecTV 40-hour DVR's hard drive failed, I had to replace it and quick.  DirecTV was not willing to send me another one unless I committed to 2 more additional years with them (I already gave them nearly 7), pay $100 for it and agree to give it back to them if I decided to get rid of my service with them AFTER the 2 years were up.  Yeah, right!  They discontinued using DVRs manufactured by other companies and decided to make their own.  And from what I hear, their own branded DVR (that does not have Tivo) is one of the worse DVRs on the market. 

I resorted to going to ebay.com...