Smallville in HD on HDNet is amazing looking (I never watched this show the first time around, but I'm hooked now. They just had the 1st season ending cliffhanger where Lana gets sucked into the tornado in her pickup truck..... WOW what an episode... this one had more action, life changing events for the characters, and neck snapping plot twists than the entire season had up to that point) The 2nd season opener is tonight and should be great. Nothing But Trailers is a good one to hunt for as you get HD versions of movie trailers, and HD movies is good if you can get by the fact that most of these films are ancient 10-20 year old films (but that could be a plus as many haven't been on any other channels for a while -- kind of like an Encore HD equivalent). The Discovery Channel HD is always good for some gorgeous visuals (hey, I remember when we paid $7 a month for that channel ALONE).
The clincher is ESPN HD though. My TV is locked on the channel from 7:30 until Midnight every Sunday for NFL Primetime and the Sunday night game. Most highlights are in HD and are not upconverted, and Baseball Tonight goes HD when it launches in the spring. Sportscenter is simply gorgeous. Compared to the rough start they had when we bashed them for upconverted stretch-o-vision, they have really stepped up to the plate and become THE killer app for HD. I don't watch as much TNT HD as I thought I would, but that's due to the fact that the Charmed and Angel reruns aren't true HD. Angel was a great show, but , like ER, I seem to have no interest to watch the show after I see it once. I didn't watch Charmed until Rose McGowan joined the show but now watch it every week..... Once I whittle down my recorded programs I might add that one when they cycle back to the beginning and Brenda, er Shannon was on it.
HBO and Showtime are always good for movies and shows during primetime...
I REALLY want Universal HD though. If they add new Battlestar Galactica and Stargate SG1/Atlantis episodes I will start BEGGING for this one. SciFi shows always seem to be more satisfying in HD....