Both are good depending on preference. I prefer the fire stick.
Fire stick Pros Better remote since it works on Bluetooth. You don’t have to point the remote directly to the box. Has your basic media controls on the remote making easier to control the show your watching.
Cons Installing google apps is a pain.
Android box Pros Easier to install apps. More of a mini pc.
Cons Box freezes now and then, so I need to unplug the power to reset it.