I love my Kindle Fire (7 inch). Got it for $80 new on Craigslist, flashed it with a new bootloader/recovery and an AOSP ROM, and it runs 4.2.2 with the best of them.
Performs almost as well as my brother's Nexus 7, and for half the price.
Make sure you get a 2nd gen Fire. It's a little harder to flash than the first gen, but it has 1GB or RAM vs 512MB on the 1st gen.