1)Total number of books owned?
I am willing to kill ten minutes on a meme post, but bugger if I'm killing a whole morning on a census. Last time we moved, books formed about half our boxes (some of which still have not been unpacked.) I'm gonna say "over a thousand" and call that good.
2) The last book I bought?
Child of a Rainless Year. Haven't read it yet.
3) The last book I read?
Re-read Raising the Stones by Sheri S Tepper yesterday. (One of my favorites of hers, perhaps for novelty--the standard set-up for a Tepper novel almost always has a shocking moment of revelation wherein long-established thing X is revealed to really be thing Z. (No! Not thing Z!) While quite a good writer, after awhile you start playing the "spot-the-revelation" game. Raising the Stones establishes early on that God is a fungus and nobody is ever surprised by this, so it works out well. And I'm a sucker for neo-fungal utopias.)
4) 5 books that mean a lot to me?
The phrasing of these meme question is odd--I could list dozens of books I really ENJOYED, but books that mean a lot to me seems like it should be something else again. Hmm.
Jinian Footseer by Tepper. And probably The Gate To Women's Country too.
The Hero and the Crown by Robin McKinley. (Well, hell, almost anything by McKinley...)
The Wounded Sky by Diane Duane (yes, it's a Star Trek novel. But I loved it so, and to this day will buy anything by Duane more or less the instant I see it.)
The Wood Wife by Terri Windling.
Mostly those are books I read obsessingly as a teen, or comfort books, or whatever. If I was going to include mere FAVORITES, instead of books that meant a lot to me, I would include stuff by Mieville and Pratchett and Connie Willis and Janet Kagan and...yeah.
5) Tag 5 people and have them fill this out on their ljs: