Just a few words about some Xmas cards or sites I receive lastly. In first place Sony Ericsson.
Some companies as CocaCola Spain (see below) make interactive microsites.
I like very much this one from WeGotIt, well done!
Also you can take a look at the video of AKQA or take part into some funny quiz as this one about the king of Spain, kingandwin, where you can win 1500€.