I LOVE mine. We loved it so much we bought two (one in family room and one in bedroom). Coupled with Netflix and our iPhone/iPad/iPod we watch almost everything through it. For us, it's a $100 one time purchase and then streaming for Netflix is about $8 a month. That's way cheaper than watching movies and TV using cable that cost upwards of $50+ a month! For TV shows that aren't on Netflix streaming, you can rent movies ($5) or TV shows (usually $.99) with Apple from the device.
With what we want to watch, that's much less than $50 a month. We counted how many shows are in a season and how many shows we want to watch and determined that it's cheaper to rent episodes than to have cable. The only thing keeping cable for you would be sports but you can rent some of that too.
Regular TV is free and you don't need anything but a TV to watch it so most of your TV shows are covered. For what's not covered, getting either Netflix or renting from the Apple TV will cover the rest. And just think, no more going out to rent if you do that now.
The last thing I do with it is that movies and music on my iPhone can project onto the Apple TV. At parties I just play music (no wires) or photos from my phone and click on a phone icon that says to show it on the Apple TV rather than the phone's screen. I also play movies I have on my computer there. All the devices need to share a wireless network. From there, the Apple TV set up is super easy.
Just think of your own lifestyle and determine if it's worth getting.
