A Samsung Android.... very good tablets.
I have the TabA with the pen, but you might not want/need the pen.
You can do anything with them that you can do with a Kindle Fire, and a lot more. You can run any app in the Google Play store, and are not limited to Amazon stuff. For reading apps I have Kindle, Nook, and Adobe Digital Editions.
Samsung electronics are top shelf.
Be sure to budget for a protective case for whatever tablet you get. I use Otterbox, although there are others out there.
If your budget won't fit the case + Samsung tablet, go with a Kindle Fire.