Njal's saga

Fantastic story, but it partially depends on which translation you get.

The saga: surprisingly readable—and relevant. An all-too-human tale of honor, vengeance, redemption; of mistakes and acceptance and occasional learning. The characters are multidimensional, believable. The setting was especially vivid after having hiked some of that area. This is a moving story about flawed people doing what they think is best in difficult times. Like reading Seneca or Marcus Aurelius, useful as a reminder of how little we've changed.

The Penguin Classics edition: outstanding. The modern translation flows well. Excellent introduction, end notes, genealogies, maps.