This past weekend, having taken four Elephant and Piggie books out of the library, we began reading them in a new way. They are perfectly designed for acting out - they consist solely of dialogue and each character's lines are located in a different-colored bubble, making it easy to identify who is talking. My daughter would pick up a book and, while it was still closed (so she couldn't see who had more words to read), pick which character she wanted to be. When she drew a character with more lines, she groaned, but gamely read on. The next thing I knew, we had read all four books. Success! I have others in the series on hold at the library and, given Willems' prolificacy (hey, dictionary.com says it's a word, as are prolificness and prolificity), we should have more to look forward to soon.
In the meantime, do you know of any other children's books that are primarily dialogue? What does your child like to read aloud?