I've been reading books on mobile devices since 1997 when my first daughter was born and I learned that I could hold a Palm Pilot and her at the same time. It was good to have an illuminated screen so she could sleep in my arms in the dark while I tapped my way through a novel.
Since then I've owned lots of different e-readers: Sony Librie (2004), Kindle (2007), iPhone (2007), iPad (2010), Kindle Fire (2011), and Nexus 7 (2012). They all have their own pros and cons, but none of them comes as close to perfection as the Kindle Paperwhite, which I bought in 2013.
A Paperwhite is better than a tablet because there's no screen glare — an iPhone, iPad, Nexus 7, or Kindle Fire is useless outdoors on a sunny day. The Paperwhite (it's on the right in the above photo) is better than my original Kindle (on the left in the photo) because the display is illuminated, so I can read it in bed with the lights out while my wife sleeps. The Paperwhite also has much better battery life than any of my other e-readers, even the original Kindle, which requires recharging every couple of days. The size and weight of the Paperwhite allow for comfortable one-handed reading. (The iPad requires propping on a pillow for reading in bed.)
I prefer reading on my Kindle over print books because I can look up definitions, translate foreign phrases into English, order new books for instant delivery, and read Wikipedia entries without leaving the page I'm on. The "X-Ray" feature tells me about the fictional characters in a book, which frequently comes in handy when I forget who someone is. The Kindle also predicts how much longer it will take for me to finish reading a book or chapter.
I'm sure a better e-reader will come along one day, but even if it didn't I'd be happy with the Paperwhite for the rest of my reading days. — Mark Frauenfelder
Kindle Paperwhite $(removed)