Mine is in my lounge. One of the few books I don't keep in my library. I bet I read it most weeks.
I first went to Avebury in 1991, and up till the TMA the only books I had were the Bord's books about 'Mysterious Britain' and the listing types of books that lumped the Roman stuff in too. I didn't have any of Burl's Stone Circle books at that point.
I waited and waited for TMA to come out, I had it as a Xmas pressie the year it was published (it was published late 1998 right?). Although I had already been to many ancient sites, it re-ignited my passion. I still take it with me whenever I visit somewhere. It's been to Brodgar, Callanish, Cork and down to the Land's End.
I've got an old astronomy book that not only talks about the stars and planets, and what they are to science, but enthuses over the beauty of the heavens. I liken it to TMA, it has the same sense of wonder. I think it was written in 1890, it's called 'Pleasures Of The Telescope'. It's a similar thing to TMA. Approaching a subject that's usually cornered by science, with the attitude of a romantic. Which is selling it way short as well, because it's so much more than that. . but you know what I mean.

Mine's a bit battered now, but it's signed to me by Copey and I bloody love it!