Right on GDA, I'd give you a high-five if I could -- Xingu does, indeed, rock!
Here is my favorite beer for this time of year: Young's Double Chocolate Stout.
http://www.bottledbeer.co.uk/index.html?beerid=142
BeerAdvocate rating for Double Chocolate: 89 (Xingu is 82)
http://beeradvocate.com/beer/profile/152/73/
If you've never tried it, I would describe it as being similar to Irish Dry Stouts though not as bitter as Guinness and a little less sweet than Beamish. As the name implies, it does have a nice chocolate accent. It's best imbibed in draft form, though you can get it in cans with the nitrogen capsule or bottled over in the U.S. I am pretty spoiled (or perhaps cursed) in the fact that I live within walking distance of a pub that regularly carries it in draft and also has cans/bottles. When I was last in London, I took the train to Wandsworth to see their brewery and got a nice tour. Young's also has a nice little pub in downtown London, on the South Bank of the Thames, near the Tate Modern, where you can have a nice lunch and enjoy a nice Double Chocolate with a great view of the Millenium Bridge and St. Paul's Cathedral -- if you're ever in London, I highly recommend!