I have firestick 4k and android T95Z plus. Firetv is ok but doesn’t have very much memory for adding things. I like the T95Z plus, have had it for awhile, has usb ports for a mouse or keyboard, wifi or ethernet. Just my opinion of course.
When looking for an Android TV Box always read the specifications Processing Power and Ram. When you find a box with high specs, go on YouTube and watch a review and make your decision then.
Remember, Android Boxes, most of them can only show Netflix & Amazon in 489p due to licensing issues. Should that bother you then the Nvidia Shield or Firestick would be the better choice, price wise they are expensive. My personal opinion, go look at the Beelink GT King TV Box, very impressive.