I needed something to stream my (rather large) collection of movies, TV shows, shorts, and cartoons to my TV. I really wanted a Boxee Box, but it was outside of my current purchasing limit (I bought several other items at the same time).
It's ok. My LG LED is Smart Enabled and has Plex support (!) through LG MediaLink built in, but LG doesn't properly read pixel aspect ratios on files (and there's also the issue of all of those HD Cartoon Network shows I bought on iTunes), nor does it read my alternate audio tracks. So the Apple TV fulfills the issue of making my videos look the way they're supposed to during playback.
However, Apple TV isn't without its flaws. It can only capably handle up to 720p (it will play 1080p files, but they will stutter and strobe like Porky Pig at a rave party). Also, while Plex automatically tags everything, Apple TV relies upon my own metadata tags, which are properly set up but aren't being read properly for items older than the 1970s. For example, my "Flintstones" and "Jonny Quest" episodes don't say 1960 or 1964, but 1981 or something. I'm going to send a complaint when I get home, because this screws up the display of 60% of my library.
It didn't seem to like my router settings, but then again, neither did my TV).
I'm still thinking I should have watched squashed people for a month and waited until I could afford the Boxee Box. At any rate, the receipt is handy. I dunno; that Apple TV interface on a big screen is almost a little scary with its minimalist look (and huge honking text; I need to see if I can reduce the text size someplace).
Also, I've noticed that some of my lower-bitrate files stutter on the TV (using either LG Medialink OR the Apple TV). Renecoding those same videos from the sources I got them from, but at 1500K instead of the 800K-1000K bitrates, significantly improved the quality...but I really don't want to have to re-encode anything. Not just because of the work involved, but because I don't have enough space - I have near-complete runs of a few Black sitcoms and I was encoding at 1000K to save disc space.