Harry Potter and the Sorcerer's Stone, by J.K. Rowling
It feels weird to say you miss a book, since obviously they're still sitting there on your shelf and you can pick them up and read them again any time you like. But I'll admit it: even though I am prone to rereading books, especially in a series I haven't read in ages when the next one comes out, I have only ever read each Harry Potter book once. Le gasp.
The reason most likely being because I didn't start reading them until after the release of the last, so I didn't have to wait for any of them. I had the pleasure of finishing one book in that morning and by evening being well into the very next with no pause. I never had to draw a breath from that world for weeks. It was a magical time, but by the end of the seventh that was the end of it forever. Like millions and billions of others, I loved these books, and though I know I could reread them again any time I like, nothing will ever compare to that very first time, when I first entered the world and met all those people and fell in love with them, wondering what was going to happen in the next seven years of their lives (SPOILER: Somebody ruined it, for example, and so I knew about poor Dobby before I even met him in the second book--oh, how I cried).
It's that first-time-feeling-excitement I miss, and although I will always love these books, a reread just wouldn't give that back to me.