Some friends bought a new house and recently asked me what I would pick given their three TV programming options (they are also interested in trying out HDTV for the first time): Comcast cable, Dish satellite, or DirecTV satellite. Here's what I answered with:
Comcast - Lots of channels on the system with a dozen or two HD channels including local stations. Downside is it can run expensive ($60+ with a basic package that includes HD, a HD DVR, and a movie channel) and the HD DVR is pitiful to use. Hopefully more HD channels are coming soon, but I've heard nothing.
DirecTV - Lots of standard-def digital channels that are very clear, sharper than my current digital cable line. They dropped TiVo for the basic DVR, and you'll have to use a new one that many people complain about. For HD, you can get a dozen or so channels on a ~$500 HD DirecTiVo combo box, but the kicker is they are changing formats in the next two years to offer hundreds of HD channels, but the HD TiVo box will no longer work. Also at the moment, most people can't legally get HD local channels through DirecTV and must use an antenna. A decent package for one TV might run about $50 or so.
Dish Network - Having never been a customer, I couldn't offer first-hand advice, but from what I've seen it is close to DirecTV in terms of so-so DVR options and some HD channels. I've never heard any rave reviews of the DVR options and the Dish Network did just lose a major lawsuit with TiVo, which could have implications down the line. Same ballpark pricing as DirecTV.
In the end I realized there isn't a particularly stand out option, as they all have significant faults and these were their only options. Also, I realized it's kind of a shame you can't get a good TV package with a good DVR even at a fairly high monthly cost. Eventually they picked Dish because they had Comcast for several years and weren't too hip on it and DirecTV offered limited HD along with HD DVR hardware that is in limbo.
Personally I'm still holding out for a Series 3 TiVo. Comcast's offerings coupled with a really good DVR would make for a great service. I just hope they start carrying more HD channels and have a plan for the future of several hundred HD channels (at which point I'll probably have to jump to fiber with Verizon and Verizon IPTV).