need advice for external display for my retina Macbook Pro.

I got my 15-inch retina Macbook Pro (Mid 2014) two months ago. It’s a fantastic machine but I am having some regrets concerning screen size. I want to be able to enjoy movies on my computer but 15-inch is just too small. So I am considering purchasing an external display for my Macbook Pro. I am thinking about a 25’’+ monitor (or TV) which can offer me closest experience to the retina one on my Macbook. I don’t want 4K monitors though, as most of the contents I consume are full HD 1080P. But I do care about PPI a lot (for browsing).

What kind of display can help me obtain this similar experience I get on my Mac? Any recommendations? Thanks.