Kindle 2
The Kindle 2 is probably the most popular ereader today. Some say Amazon has over 60% of the ereader market because they've done a great job of packaging the reader with their extensive collection of books. Although nowhere near as flashy as the iPad, the Kindle does the job of allowing you to carry a lot of books with you in one easey to use small device.
Pros: The Kindle is easy to use and has built-in global wireless connectivity. It is small, light weight, and fast. You can shop the Kindle store from just about anywhere without having to rely on WiFi access. It holds up to 1500 books, newspapers, and PDFs, and is faster than the Nook at turning pages and downloading books.
Cons: The Kindle is a closed device meaning it does not support other ebook formats out of the box. There is software available on the Internet that will allow you to "hack" the Kindle, but it's likely against Amazon's policies to do that.
Price: $259
Nook
The Nook from Barnes and Noble looks sharp. It runs Google's Android OS and has had several software updates since its release. Although not as popular as the Kindle, the Nook is a solid ebook reader.
Pros: The Nook has fantastic contrast and makes books easy to read. Compared to the Kindle 2 it outperforms in the contrast area. Running Google's Android OS allows the Nook to offer better web browsing and gaming features. It also has an microSD expansion slot under the back cover. The nook uses WiFi to connect, and the B&N store has over 1 million books available. If you have a problem with the Nook you can take it to a Barnes and Noble store for help.
The Nook allows users to share books with friends, and access free WiFi at all Barnes and Noble locations. It also supports the open ePub book format. The Nook has a color lcd that allows you to see color versions of book covers. The soft keyboard is not as responsive as it should be.
Cons: The Nook is slightly thicker than the Kindle and is much slower. Booting the device, loading books, and turning pages all take about twice as long on the Nook.
Price: $259
iPad
The iPad provides the best looking reading experience. In typical Apple style the iPad is elegant and makes reading fun.
Pros: The iPad is elegant and fast. Reading on the iPad is fun as long as you don't read for hours and hours. Page turning is fast, and the iBooks application allows you to read the open ePub standard. The iPad's search function and font sizing make it a top performer.
If you've been using a Kindle, you can download the Amazon Kindle app for the iPad. It works very well and allows you to have your entire Kindle library on your iPad.
Cons: The iPad's backlit screen can cause eye strain if used too long. The iBooks store has a very limited selection of books. The weight of the iPad is prohibitive in some situations like reading in bed.
Price: $499 - $829
Conclusion
If you only care about making reading fun, the iPad is for you. If you read for a long time you will find less eye strain with the Kindle or Nook. When comparing the Kindle vs the Nook it comes down to features and speed. The Nook would probably be favored by techies who want to be able to load their own content, hack the device, and surf the web. The Kindle has the smoothest experience with fast performance and a better selection of ebooks through Amazon.
Winner: Kindle 2