The great thing about GJSS is how many emotions it drags up. I guess I've come up with 15 different ones, maybe this isn't the same for everyone, but these are mine, feel free to add:
First, the anticipation about it opening up for the new year.
Then, the anticipation about it closing and seeing the head count of those opting in.
Next is the anticipation of who you're going to draw and what do you get them.
When you find out whom you've drawn, now its down to brass tacks on how to gift them. The clock is ticking.
Now its aquiring the gift or gifts, either by shopping local, shipping from a third party, handcrafting an item, having someone else custom craft an item for you.
Next is making sure it gets shipped in time for the recipient to receive them before Christmas.
The agony of tracking the shipment hoping it gets there on time.
The anticipation of them posting their photo of said gift and their wonderment of what it is and who sent it.
Finally being able to open your gift to see what you received. I have never, ever been disappointed.
Posting what you received and writing the thank you.
Seeing the responses to what others think of what you received.
Seeing the response of the giver on how much you liked it and often their thought process of what to send. (I get ideas from these for future GJSS.)
The constant refreshing of the thread to see what everyone else gets and the responses of those.
The Polar Express has a scene about the first gift of Christmas, we get concerned about the last gift of Christmas, hoping no one gets Grinched and if someone does, seeing the great members who go out of their way to send a second gift to make sure everyone is taken care of.
And finally, dreaming about how you'll top what you gave for next year. The getting is great, but the giving is magical.