Last year I got hold of an Apple TV and have to admit I haven’t used it very much, if your full invested in the Apple ecosystem then its great but I am not.
I found it more useful once I got the alpha version of Boxee on it, but the once the beta version came out for the PC I found the old alpha a bit limited. The Beta version of Boxee is much improved over the alpha version and now you can get the Beta version on an Apple TV.
On the Boxee blog they have instructions on how to hack your Apple TV to get the beta installing (if you have the alpha it looks really easy). Read the blog post for full instructions.