I always take mine down the 26th or 27th. This year we got a huge tree and we have tons of lights and ornaments--so this is a big job for me! My husband works late, though--and I can't have him help, so I just sort of roll my sleeves up and do it. The hardest part was dragging the tree out the front door and removing the water with a turkey baster (took forever) so it would not spill. It feels so good to sweep and vaccuum and get all of those needles up, though. Our livingroom now looks so clean and open.
It is always a little sad to take it down, but at the same time I love cleaning up the livingroom and getting the house ready for the new year to come. For me, when Xmas is over, I don't like to see the tree anymore. The kids don't mind at all. When I was little my mom was such a procrastinator that she would leave the tree up very long into January--which sort of depressed me. I was glad when I got my own house that I got to pick when to take down the tree.
The kids and I always sing a little song from an old cartoon "Christmas comes but once a year, and now it's here, now it's here..." when we put up the tree, and when it comes down we sing "Christmas comes but once a year, now it's gone, now it's gone--and so we say so long..."