We all really admire the Seamus Heaney translation, and the accompanying audiobook. It's amazingly accessible, especially in the spoken word.
Tolkien's translation is of course a classic, if a little more focused on technical linguistics than sweeping poetry (no surprises there!). It's worth mentioning 'The Monsters and the Critics' by Tolkien, which contains some very important influences on BEOWULF: Age of Heroes. Particularly Tolkien's (rather romantic, but engaging) ideas about the contrasting historic pagan and Christian world views.
We're very much looking forward to Maria Dahvana Headley's new translation too.
In the public domain, we've enjoyed Grummere's work. William Morris and A.J. Wyatt did very poetic translations.