The North Pole Sleigh Ride Adventure is one of the nicest things you can do in Second Life for the holiday season. Curl up in a sleigh under a blanket and watch as the ride flies over polar bears, giant candy canes and christmas treats, and ice skaters all in a gorgeous winter setting. You end up in a very pretty Christmas Village, where you can sit in Santa's Lap and ask for your gifts.
Set your sky to "grey sky moon" for a nice effect in Windlight under "advanced sky" in Environmental Editor if your viewer (like Firestorm) is so equipped.
SLURL to beginning of sleigh ride:
I made a video of the sleigh ride in 2011 which you can see here are the end. The ride has some updates, but is much the same for 2013. Make sure to visit if you have not yet done so.