Back in June, we highlighted the release of James Joyce's Ulysses in free audiobook format. Ulysses stands as Joyce's most important work, and for some, it's most the important work published in the English language during the entire 20th century. Despite Ulysses' enormous stature, many readers still turn to Dubliners, a collection of 15 short stories that Joyce published in 1914, partly because it's considered his most accessible writing. Over at Librivox, you can find several key stories from this collection -- namely, The Sisters (mp3), Araby (mp3), Eveline (mp3), and The Dead (mp3 in zip file). The Dead is the longest and last story in the collection, and it's a Christmas story, some say the "greatest of all Christmas stories," which makes it particularly timely to mention here.
It's worth noting that you can download the complete etext of Dubliners at Project Gutenberg or on Google Book Search. (The latter version is cleaner.) And, if you can suffer through it, Gutenberg also offers a free audio version of Joyce's text, which is read by a computer, not a real person.
Lastly, be sure to spend some time perusing Librivox's entire collection of free audiobooks. It's the best on the web.