i don't think it's worth it. remember it's AppleCare not AppleCare+, which means it does NOT cover accidental damage.
plus, you get 1-year warranty anyway, and probably get up to 3 years depending on what credit card you use.
even if it's only 1-year, do the sample math,
AC is $30, the Apple TV is $150, unless the possibility that the ATV fails in 2nd and 3rd year is more than 20%, it's statistically not worth it. if it fails, just go buy another one.