i would like to mention that Netflix is actually a combination two services, which you pay for separately but share a common interface (at least on PC): an online web-based video streaming service (with HD for compatible players/TVs and movies/TV shows) and an dvd/blu-ray renting service thru snail mail.
its like $8 US for each service. i pay for my parents to have the renting service (they are poor and only have dial up), and i have the streaming service with my high speed internet through my PS3 (or my wife's ipad2, or my computer, or my laptop, or my android phone, or my 3DS (seriously!)). we dropped the rental service because we're lazy and too impatient to wait for a few days.
its better than cable most of the time (but they are behind a year or so with TV shows), and allows you to veg out and watch say... all of star trek. or x-files. or hundreds of other older TV shows.