The Divine Comedy by Dante (in a terza rima translated by Peter Dale)
I read the Inferno a long time ago in an awful 1960's translation that put me off the Italian super-bard for ten years. I would never have returned to The Divine Comedy if I hadn't met Peter Dale in the shop one evening. This charming man was so passionate about the art of translation, so funny and also generous and kind (he gave me a slim volume of his own poetry because he liked the shop) that I felt I had to read his version of Dante.
Faithful to Dante's own rhyme scheme he has also managed to make the Italian epic flow and make sense to the modern reader in English.
Re-reading Milton's Paradise Lost last year I found my imagination burning with intense images and this version of Dante has the same effect. I even dreamed of being chased by Devils the other night! (I would put myself in the same ring as Virgil - with the virtuous pagans. Although several of the other, more nasty rings, contain sinners guilty of crimes I'm sure I have committed at one time or another - hence the guity dream?)