I can also sense that I'm rather starting to go down the route of an English castle -- but can you really blame me? Let's continue -- trophies would be great too. What if you could have the heads of bosses you've slain on your wall? Garrosh's head on a pike seems a fitting revenge. Onyxia's, too, like an old-fashioned hunting board. Of course, you would likely have too many to display unless your garrison was huge, but still, you could pick and choose the coolest heads or your greatest victories.
Looking more at the real home aspects, I'd love it if the garrison had things like sleeping quarters, an inn-style bedroom where I could put my character to sleep before logging out. I don't know why, but it's something that appeals to me. WoW Insider's hunter writer, Adam Koebel, immediately chimed in with pets -- he'd like to see his stable of pets roaming the area. And I would love a similar thing for all minions, pets, demons and such. Battle pets, too, you could choose a team to have wandering around. Or maybe it's just your current team, or a random assortment.
I'd love specific rooms for your professions -- so an alchemist would have a Dickensian laboratory, a blacksmith would have an anvil, maybe a tailor would have a loom, and so on. To me, it seems, the way to make a Garrison a home is to have it be a building that reflects your character or characters. And isn't that what a home is, anyhow? What are your ideas?