Sideways Stories from Wayside School, by Louis Sachar. (Avon Books, Humorous episodes from the classroom on the thirtieth floor of Wayside School, which was accidentally built sideways with one classroom on each story.
Corduroy by Don Freeman is the first in a long series of picture books about little teddy bear. In this one he's living in an apartment store, forgotten on a shelf long enough he's lost one of his buttons. This book is part of my childhood!
sweet valley high series (book 1 by: Francine Pascal). I read these at the age of 12 and loved them, a new book came out every week that I can remember and mum would get me one. I nearly had the whole collection.
Frog and Toad are Friends. This "I can read" book by Arnold Lobel is truly charming. It is full of great wisdom, depth and insight in the simplest of terms and stories. I am still enchanted by this and the other Frog and Toad books.