I have 2 appleTV's, and use them both every single day, for multiple hours a day.
Kids shows, and then TV shows, I have no use for satellite TV. The only time I am not on the AppleTV is when I have to turn on the xbox to use Netflix.
Now, alot of my AppleTV viewing is of shows I manually put into the itunes library, movie and TV shows converted to mp4, so if you're willing to go through the hassle of ripping your DVD seasons of shows or *whatever*, it's indispensable.