NO CABLE COMPANY DVRs.

TiVo is the only option if you care about usability and power.  They are easily hackable, so go buy a 1 TB Western Digital Green drive for $60 and swap it in.  

Watch any recording from any computer.

Netflix subscriber?  You get free, instant streaming through TiVo for free.  HD quality if you have a good internet connection.  Blockbuster's entire catalog is coming to instant streaming too.