Hi. I have a Sony smart TV that does not have a browser, Gmail access, etc. I was reading up and came into a conclusion that buying an Android TV device would be a good bet. Something under $100 that I could plug into hdmi port and perhaps use a wireless keyboard and mouse to browse around. Any thoughts?
Currently, the most cost effective device with full Netflix and Amazon Prime resolution that also features an USB port (e.g. for RF receivers) is the Xiaomi Mi Box S , which costs around $60.
Beware of all those little known Chinese brand boxes since they only allow you to play Netflix at 480p due to DRM restrictions, often use Tablet Android versions (yep, that's crazy) and often have issues like broken sleep modes, memory bugs and system crashes.
As with any Android TV device which features an USB port and Bluetooth, you can add plenty compatible devices. There are also some compatible USB hubs in case you need more than one USB device.