My first ebooks, purchased through the Google ebookstore, read on a Samsung Galaxy Tab as I traveled for the holidays:
The Tab is just the right size to hold on one hand, the screen is bright but not tiring for my eyes, and the battery lasts for a whole day of reading. And the Tab also does all those useful Android things, which is especially convenient on WiFi-equipped planes (US Airways, please, please, put GoGo on the rest of your Airbus fleet). The Google Books app is simple and functional.
What's missing is a means of sharing books with family, as we do all the time with paper books.