To start off the month of December, B&N's freebie pick is an appropriate one.
Happy families are all alike, and never invade Russia in winter. Although this is kind of a downer for Xmas reading and maybe the holiday they have in mind for this week's selection is
Festivus.
Anyway, the first B&N Classics holiday promo title of December is
Leo Tolstoy's
Anna Karenina.
It's an old public domain translation, so the language may be a bit clunky, but this one has a nice introduction that goes into the themes of the book, and you can always skip straight to the endnotes explaining the background and customs of the novel to complement whatever modern version you may be reading.
Since this thread has gotten so long, I've edited the first post for the benefit of anyone who's clicking for the first time, so they hopefully don't get disappointed when they find that
Grimm's Fairy Tales is no longer free.