The first Dante I read was the Ciardi (over thirty years ago!, argh!), so I'm already prejudiced...but I confess to a weakness for "poetic" over "literal" translations, particularly those that try to preserve rhyme scheme, and other "poetic" qualities. The Ciardi is, I think, undervalued today largely for that very quality (though it beats the heck out what I've read so far of the recent Ciaran Carson, IMO, which I bought on the strength of a glowing review, hoping it'd be sort of like the wonderful Ted Hughes Tales From Ovid; my disappointment began literally at line one, but I haven't got back to it yet so I'll suspend judgment).
Anyway, for a fine literal translation -- complete with the original Italian on facing pages, which is great -- the Allen Mandelbaum has everyone else beat at present; and I don't believe in reading only a "poetic" translation, preferring to follow up same with a solid literal version. Ciardi tries to preserve Dante's terza rima by rhyming the first and third lines (which forces some invention, of course), and also refuses to shrink from "unorthodox" stuff in the original -- as in Dante's discussion of the Roman goddess Fortuna, conceived of as disposing the fortunes of man under divine direction. To echo the specifically female qualities this involves, Ciardi translates "general ministra e duce / che permutasse" using the wonderful phrase I mentioned before...and I hope that during its fiftieth anniversary, Ciardi would forgive my "fair use" quoting of a few of his lines, here, including that one:
That king whose perfect wisdom transcends all,
made the heavens and posted angels on them
to guide the eternal light that it might fall
from every sphere to every sphere the same.
He made earth's splendors by a like decree
and posted as their minister this high Dame,
the Lady of Permutations. All earth's gear
she changes from nation to nation, from house to house,
in changeless change through every turning year.
No mortal power may stay her spinning wheel.
The nations rise and fall by her decree.
None may foresee where she will set her heel:
she passes, and things pass. Man's mortal reason
cannot encompass her. She rules her sphere
as the other gods rule theirs. Season by season
her changes change her changes endlessly,
and those whose turn has come press on her so,
she must be swift by hard necessity.
And this is she so railed at and reviled
that even her debtors in the joys of time
blaspheme her name. Their oaths are bitter and wild,
but she in her beatitude does not hear.
Among the Primal Beings of God's joy
she breathes her blessedness and wheels her sphere.
-- Dante, Inferno, Canto VII, lines 73-96, John Ciardi translation (1954).
*Sigh* :)
93 93/93 -- AJ
Dante translation comparisons: http://www.carthage.edu/dept/english/dante/Index.html