One of my absolute favorites: turning on the tree lights early in the morning, while the house is still quiet and dark. Len had to hunt all over this year (MANY stores were sold out even two weeks ago!) to find enough working strands, but his efforts were well worth it. We decorated our Christmas tree this weekend, and it's beautiful, but I'd be satisfied with just lights and the treetop angel.
Coziness: sipping hot hot chocolate [as opposed to warm hot chocolate :-)] while watching a dvd with Len in a quiet house. David got us interested in Burn Notice, a tv show about a burned spy stuck in Miami. There are the gratuitous shots of bikini-clad women (who probably don't drink hot chocolate), but so far the episodes are fun (tricks and cons) and short (no commercials!)--light entertainment. We're only a few hours in to the first of three seasons, so consider this a preliminary recommendation; some acceptable shows seem to push the envelope more as time goes by.
Also popular: listening to Christmas music. Right now my favorite cd is John Michael Talbot's The Birth of Jesus, because it includes some gorgeous Advent hymns: "Of the Father's Love Begotten", "Let All Mortal Flesh Keep Silence", and "Lo, How a Rose E'er Blooming", as well as "What Child is This" and "O Come, O Come Emmanuel". I'm happy to putter around the main level (or more likely, in the kitchen), listening and singing along.
I'm noticing that everything on my "happy list" is quiet and solitary (or nearly so). I read once that there are two kinds of people: those who recharge by socializing and those who instead need solitude. While I do enjoy the company of others (and have only lived alone for a few days in my WHOLE LIFE, which I did NOT enjoy), I am absolutely a quiet time re-energizer.
Whichever you are, I hope you are treasuring these last few days of Advent.