Kindle app best ereader?
Personally I will disagree because Stanza was far better before Amazon stripped it. With only limited exceptions I consider the iBooks app as superior because it gives you the ability to categorize your library and gives you a more book-like reading experience; though it has its limitations as well.
I'm also opposed to Flipboard because I rarely find my "social" acquaintances interested in the same news that I follow. Zite, on the other hand, fits my interests nicely.