Here is my list for the top ten picture books for 4th/5th graders. I am answering Cathy's challenge http://reflectandrefine.blogspot.com/ from her blog 1. The Watertower by Gary Crewes. Boys love this book. Its science fiction which is really hard to find in a picture book. The pictures have "clues" hidden in them. I had to read this book three times and really STUDY the illustrations to understand it.
2. Mysteries from History: The Mary Celeste written by Jane Yolen. She wrote four of these books but this one is my favorite. The text features are really interesting as well. If you can get the kids hooked on this one they will read all four.