Originally Posted by TheDA

I'd go with 4K. If you get one that has upscaling(I think most do) even your HD content will have more pop.

Netflix and Amazon have a load of 4K content and Sky UK are now gearing up to broadcast in 4K also. Depending on your interests there may be a lot of 4K content on YouTube and Vimeo also. For broadcast 4K you are going to need a decent broadband connection. 20Mbps or higher probably.

Film studios are releasing more and more 4K content as well now, 3 or more releases per month.

One other thing, you probably don't want to go any lower than 48".