There are quite a few out there. It's difficult to say which is best. Look for a box with Amlogic S912 chip, it is the most current one. The boxes with S912 are for about $60. The important thing with TV boxes is updates. Some manufacturers don't really provide a software update. I had an MX2 Tv box, but now I am planning to get a Beelink S912 box.
You can also check this website. It has good info about the latest Android TV boxes.
https://androidtvbox.eu/