Because everybody who is an anime lover is not allowed to watch anything not from Japanese origin. I love anime, but sometimes there are a few western series and movies which are truly gems.
Depending on how GOT might unfold it will be one as well.
The Walking dead went from 'Good' to 'Sucks' after the second season.
Prison Break a few years back was a gem up till a certain stage as well.
Breaking Bad.. I dropped it. Might give it a try and skip season 2/3 because it's too much of the same.
And then we have Vikings. It's a small gem right now, the actors are great, and really play their role well.