I used Diamond TV tuner usb 2.0, it was fancy hardware but then I got black screen flases and it was actually cutting out the tv signal, I returned it to BestBuy and got Win TV which was great to use.
I decided after a year of that to upgrade to an HDTV usb tv tuner, I wanted the best one so I ordered the Cats Eye HDTV tuner, I paid 200 USD plus shipping to Canada, I'm all excited...... then I am wondering where I plug in the audio, video or hdmi, oh wait... the Cats Eye usb tv tuner is for Free Over the Air (those cheap 10 antenna's for people without cable) and doesn't support cable tv, satellite or digital cable.
I've also tried the ATI wonder usb 2.0 which was on sale at futureshop for $80 canadian and it was comparable to Win TV, however WIN TV was the best.
Now I hope the HDTV usb tv tuners aren't so misleading, Maybe they'll learn from the refunds of people who don't like paying $200 for 2 channels.