The trouble with Smart TVs is that they can be pretty poorly maintained when it comes to software updates; a year or two in and they're basically abandonware. The only thing I use mine for (app-wise) is Netflix, because all my servers and things are Linux-based and can't do DRM. And the Netflix app is terrible.
If my home setup were Apple centric (and I didn't develop this sort of thing for fun and profit), the Apple TV would be all I'd get.
The reason I recommend it is because you'll be able to access all your content from your various computers -- certainly anything that can be put in iTunes, and that includes movies you rip yourself with third party software like handbrake or source in other ways we won't go into -- and anything that it doesn't provide an app for you can fling at it from one of those devices. And it does have the characteristic Apple virtue that what it does have is less broken than everybody else.