I actually prefer the smell of old books to new. They smell warmer.
Texture of paper is also important to me. I heartily dislike glossy paper. The paper should fit the book.

Edit: I just realised I didn't actually answer your question. I love the weight of a book when I read it. The texture of the cover. This is one of the reasons why I prefer old books to new. They never take the same trouble with binding now it seems. I like the new tendency to publish the history of the font, though. It is usually quite interesting to read. It is not the main focus for me, though. If the font is good, I only give it cursory attention, as it is too close to the entry into the text itself. But the wrapping, the texture, the feel of a book, that I find essential.