There's also a generic Chinese model for comparison, even though the specs look good, don't buy it, they still seem to have quality issues. If you get a good unit, great! You can play games through the Fire TV Stick, using Amazon's new controller. We're not sure if the others will work with generic Android controllers, since there's no Bluetooth. Roku used to do a game controller for its second gen models, not sure if it still does.
If you're in the Amazon Prime family and play games, then the Fire TV Stick looks a good bet, otherwise the Roku still gets our vote with the massive amount of content.