Kate DiCamillo's Bink & Gollie books are just the thing.
Bink and Gollie are best friends who are quite different from each other, but that doesn't stop them from being good and loyal friends who love one another unconditionally. They're great to read aloud because the dialogue is witty and quick, and the stories are interesting. Alison McGhee's illustrations are full of movement and expression, and they keep the story moving right along.
Here are a few choice lines from Bink & Gollie, Best Friends Forever:
"This Acme Stretch-o-Matic is top quality," said Bink. "I can feel it working already."
"Well, as far as collecting goes, you've got your rubber worms," said Mr. Eccles. "You've got your gold star stickers."
"You've got your decorative thimbles," said Mrs. Eccles. "You've got your rings made out of spoons."