Frankly, I've found the ATV one of Apple's most disappointing products. I don't use it much and there was certainly a period of time when it was having real software problems. For a while it wouldn't connect with iTunes very well and browsing movies was a pain. Also the selection of movies is limited and unpredictable. Things come and go from the selection and that is annoying. That said, I watched the Hangover a few days ago on it and it worked perfectly. Within two minutes of starting the download, I started the movie and watched it straight through in "HD" (Apple's version of HD that is) and there wasn't a single hiccup. Things seem to be working better these days, but the box still has problems. I hate that I can't turn it off. That's just a stupid feature. And the remote is all sleek but really lacks some functionality.
So I can't really see why anyone is buying it these days. I also have an XBox 360 and Netflix, so I use that at least as much as I use my ATV. That's a cheaper solution because I'm also a gamer and would have the XBox 360 regardless of its movie playing ability. But Netflix gives it free downloads for a $10 per month subscription and the selection is about the same as Apples (i.e., not too great). So why add another box? (Why did I do it? Because I bought the ATV over a year ago and there was no Netflix. Also I'm a Fanboy and I thought ATV was going to get movie selections like iTunes has records. Boy did that not workout at all. The selection is still very hit or miss.)