I'm doing just that with 24 and I've just watched Fringe in HD on my TV from my laptop.
You'll need a cable for the video and a seperate once for the sound.
How big are HD files to download?
Can anyone recomend the cables then i've got a Fujitsu Siemens laptop and Sharp Aquos 1080p HDTV? I don't no a great deal about technical stuff cheers.