Kindergarten: Willy and Hugh by Anthony Browne.
Grade 1: Dr. Drabble's Spectacular Shrinker-Enlarger; Dr. Drabble and the Dynamic Duplicator by Sigmund Brouwer and Wayne Davidson. (See also: http://www.coolreading.com/)
Grade 2: Goose's story by Cari Best. If you liked the movie: Fly Away Home, you'll also enjoy this book about a goose who arrives at the pond one spring with a mysterious broken leg.
(See also: http://us.macmillan.com/author/caribest
Grade 3: The Boy Who Ate the World (and the girl who saved it) by Don Gillmor and Pierre Pratt. Students were tickled by this hysterical tall tale.
(See also: http://www.mbwriter.mb.ca/mapindex/g_profiles/gillmor_d.html)
Grade 4: Missuk's Snow Geese by Anne Renaud. A sweet tale of how a girl helps her father find his way home in a snowstorm.
Grade 5: Sydney And Norman by Phil Vischer
(See also: http://www.philvischer.com/?page_id=70)
A parable with a surprising and arresting twist.