The DS has lots of hit titles over in Japan, but none as big as Pokemon Diamond & Pearl. Nintendo announced today that the latest portable RPG entry in the series has sold a total of 5,000,000 units across its separate Diamond and Pearl versions. This feat comes less than three months following the 9/28 release.
As part of today's announcement, Nintendo stated that Diamond & Pearl are the best selling titles the Pokemon series as a whole has seen in Japan. We'll have to wait until some time next year to see if the success can be replicated internationally.