I have an Nvidia shield (first gen) and its been rock solid. Never used it for gaming. Always streaming. Also acts a a Plex server. Very power little device. If thats to expensive look at the Mi Box, Same thing minus the controller and gaming stuff.
I prefer Roku. Amazon, Google and Apple all seem to allow other content currently but that has not always been the case. As Roku is independent they seem to do the best to support any service.
Any of the basic streaming devices are cheap and sufficient for what you need. Looks for black friday deals and get something cheap.