Recommended edition: The Divine Comedy, ed. Robin Kirkpatrick (New York: Penguin, 2013).

From the publisher:
An epic masterpiece and a foundational work of the Western canon, The Divine Comedy describes Dante’s descent into Hell with Virgil as his guide; his ascent of Mount Purgatory and reunion with his dead love, Beatrice; and, finally, his arrival in Heaven. Examining questions of faith, desire, and enlightenment and furnished with semiautobiographical details, Dante’s poem is a brilliantly nuanced and moving allegory of human redemption. This acclaimed blank verse translation is published here for the first time in a one-volume edition.

Online:
Gutenberg Project (free version)
Amazon (recommended version)