The Kindle Fire tablets I love, but it's hard on the eyes for reading.
It's looking at a computer screen to read a book.
If you think you can do that, then go for it! The Kindle Fires (as a kindle fire owner myself) are great Tablets.
For reading I prefer the classic kindle or the new paperwhite. They make it so much better for your eyes.
Nooks are the competition from Barnes & Noble's company.
They're good devices, as well. I'm just partial to the Android operating system's that power Kindle's.