I own a Nook Color - the $249 version that was available the January before Kindle Fire came to pass. I held out waiting for a touch-screen tablet-style digital reader because touch screen was the deal-breaker feature for me. Nook finally won my business because the Nook Color came onto the market before the Kindle Fire. It was a shiny, awesome novelty for a few months...and then it got old.
Not the device itself - the device is fine, even though the touch screen is a little sticky through the screen protector. What got old was being a Barnes & Noble digital customer. Browsing from my Nook was a tedious experience and I more often than not found myself at Amazon browsing, then going to Barnes & Noble to look for the title (and sometimes being frustrated because Barnes & Noble either didn't have it or charged more for it). I found myself more and more picking up my Nook only to find the battery was dead, so I had to recharge it and wait to read--so by the time it was re-charged, I no longer had time to read.
And then the Kindle Fire came out and I was a little mad at myself for not waiting a few more months, then buying the Fire. Grr.
And I used my Nook even less...and more less...until I started thinking about asking for a Kindle for Christmas. It doesn't even have to be the fancy tablet (I'm over the gadgety-ness of that). It just has to be a Kindle. I might not even wait for Christmas. I want to be able to comfortably read now, darn it! Maybe for Octoberfest instead of Christmas... :)
In any event, I'm curious what reading device you use. Are you a Kindle user or a Nook user? If Kindle, did you use Nook first? If Nook, did you use Kindle first? Do you not use either of the big devices, and instead use something different? Why did you choose the reader you've come to love?