What I use is a chrome box. I have been using one for years. Plex, Amazon video, netflix, hulu (back when it was free), youtube, nbc.com, nickjr.com and pretty much any site that does streaming. My 4yr old plays games on nickj.com with it. Use a logitech k400 for input.

I would definitely recommend one with at least 4gb of memory. We used to use the 2gb for years, but as resolutions increased, we would run into more and more stuttering issues and having to reboot. But once I upgraded the ram, all of that went away. We actually have 6gb of ram in it currently, though I feel 4gb will do just fine.

We have a separate gmail account just for the chromebox and will send it links via hangouts to open if we don't feel like re-typing it out/searching.