Sunday Ticket and AMC HD are deal breakers so DirecTV wins for me. I came from U-verse to Time Warner Cable to DirecTV. DirecTV by far has the best HD quality of the three and has the most responsive interface for dvr and channel guide.
Seriously? One of the things I've noticed with friends who have Dish is their lightening fast DVR response. The slowness of the DTV guide, the frustratingly long delays when encountering DTV Banners on a guide page, is lately getting to the point of being unacceptable... to me anyway.