Picture quality of various services

via Wired.com

From best to worst:

1 Blu-ray
Full 1080p resolution pumped out at up to 48 Mbps = the best picture quality currently available.

2 Over-the-air broadcast
Even though they use the older MPEG-2 standard, networks broadcast HD at a high data rate (about 19.4 Mbps), which puts cable and satellite to shame.

3 Cable/fiber (tie)
Cable companies use proprietary compression and won’t talk about bitrates, but the consensus is that they best the satellite services in picture quality.

4 Satellite
Dish Network and DirecTV won’t talk about their tech either, but engineers believe that both providers transmit their HD programming at around 6 to 8 Mbps. Good enough for fourth place.

5 Vudu
Walmart’s Vudu is the only video-on-demand service that offers shows in 1080p resolution (and with a decent data rate, at that), making it the highest-quality download service.

6 DVD
Although DVDs aren’t hi-def in resolution, their transfer rate of up to 9.8 Mbps means their quality is better than what most streaming services offer.

7 iTunes/Amazon (tie)
A hefty helping of compression and lower bitrates (around 3 Mbps) means a drastic falloff in quality from most download services.

8 Netflix
InstantNetflix emphasizes seamless playback rather than picture quality. The slightest hiccup in your broadband connection seriously ratchets down the fidelity.

9 Hulu
Put regular Hulu on a big screen and you’ll be constantly reminded that you’re watching TV over the Internet.

Read More at: http://www.wired.com/magazine/2010/08/ff_howto_watchtv/7/#ixzz12O8ysTNm