I love Christmas trees, and so do the Hellions, but for different reasons. The tree is basically a cat playground, and since we acquired the Hellions four years ago we haven't put anything breakable on the Christmas Tree. We could probably take some extraordinary measures to keep them out of it, but they have so much fun I actually feel a bit guilty depriving them of their seasonal escapades.
I am hideously allergic to real trees (pine, fir, oak, any trees, all trees) and so we always get fake ones. I like to get free fake trees on Craigslist of Freecycle and then give them away after the holidays so I don't have to store them all year. This past December I decided to get a 3' tall tree, both to save space and to maybe discourage the Hellions from enjoying it quite so much. It's too short to climb, so they can't climb it, right?
While they can't technically climb it, they can wrestle it into submission, which they did at every opportunity. The poor tree never spent more than five minutes upright for the entirety of its career here. The Hellions still had fun, though.