The originality of the story is what makes Eden of the East a good anime to watch.
The art, background, characters are all masterpieceish. Especially for an anime series. The characters look more real than your average anime.
The reason the anime is not the best of all time is presentation of the story. Although the story is original and awesome, it was executed in a weaker fashion. This may have been on purpose to make the anime a sort of a relaxing and enjoyable instead of on the edge of your seat sort of thing. The ending made me want more, and that makes things frustrating.