There's some classics on my 'recommended' list as well as new, and not-so-new.
Musical DVDs first. I heartily recommend Pink Floyd: Live At Pompeii and Iron Maiden: Flight 666. They never get old, for some reason.
Movies. Obviously, although it makes Christmas a bit like groundhog day for the last eight years, there has to be the last Harry Potter. And of course the Star Wars Blu-Ray collection. It wouldn't be Christmas otherwise.
DVD series box sets include Absolutely Fabulous, the IT Crowd, Comic Strip Presents... (anyone remember those? Who launched Jennifer Saunders, Adrian Edmondson and Keith Allen, among others?)
Other blast-from-the-past box sets you can still get include Black Books, Gimme Gimme Gimme, The Young Ones, Bottom, Filthy Rich & Catflap, Red Dwarf, The New Statesman, Blackadder, and Girls On Top. And if your budget reaches, check out The Golden Girls. Classic Betty White!
If you haven't seen it, definitely get Bridesmaids - it's a hoot!
From the newly-released, there's The Inbetweeners Movie and Horrible Bosses...
And it has to be Super-8. Steven Spielberg back on his best form in this one. Saw it in the cinema, and felt just like being a little kid again, watching ET for the first time :)
If it was out sooner, I'd also add Cowboys & Aliens. Just thinking of Daniel Craig's method of concluding an awkward confrontation with a good... well, it makes me smile :)