I got my very first Kindle way back in 2009 (see review here) and it was love at first sight (thanks sis!). I've since then replaced it with the Kindle Fire in 2012 and have used it almost daily ever since.
My favorite thing about it is the books. That is the main reason I bought the Kindle. They are so easy to download, I can borrow them free from my library online, read them free with my Amazon Prime membership ($79 a year) or buy them from the Amazon store.
An unexpected benefit is being able to watch almost anything. I can log into HBO GO and watch Game of Thrones. I can log into my Netflix account and watch movies. I have the Amazon Prime membership which allowed me to watch the complete Star Trek Enterprise series and Arrested Development, both of which I missed when they were on TV. I've been able to catch all the new Under The Dome series based on the Stephen King book.
Another unexpected use was discovered courtesy of my nieces ages 5-8. All 3 of them have played the various games I've downloaded for them at one time or another. Favorites have been:
Baby Care & Dress Up - Play, Love and Have Fun with Babies
Fairy Tale Princess Dress Up
For hours. And all free.
I've also listened to my Adam Carolla podcasts and been able to transfer all my iTunes music with the Amazon music importer. The speakers are soft, but I've found a free app, Speaker Boost, that boosts the sound nicely and if I want, I can just plug in my earbuds.
The battery life is much better than any of my other portable devices (laptop, smartphone, iPod, I'm talking to you) and the screen quality and touch sensitivity is perfect.
And if anyone is ever wondering what gift I would love, an Amazon Gift Card is the perfect gift. Forever.