Fair for Its Day: The Chinese Conjurer and Tiger Lily are pretty broad stereotypes by modern standards, but they were fairly progressive for the time by being friends to Rupert instead of Yellow Peril villains. They have also always been drawn in realistic style, without the gross racial caricatures seen in some other contemporary works.
Narm Charm: Most long-time fans will admit it's rather silly, but a charming sort of silly.
Hilarious in Hindsight: "Rupert and the Chalk Drawings" involves Rupert Bear and Gregory Guinea Pig entering a world inhabited by erased chalk drawings. Bear in mind that the episode aired years before ChalkZone came to be.