With the new Nintendo DS comes a new generation of Pokemon. Pokemon Diamond and Pearl. Both games are almost exactly identical but I'll just refer to them as Diamond and Pearl since it makes things easier.
Pokemon Diamond and Pearl are fourth generation Pokemon games. Having come from the old Gameboy to the new Nintendo DS many new and old features are available in these two games. Using the Nintendo DS's Wi-Fi connection players can find themselves battling people across the world. With the Wi-Fi connection players can much more easily trade Pokemon at the Global Trade Station. At the Global Trade station you put up a Pokemon that you have, state exactly what you want for it, and have someone trade with you. A very effective system of trading.
With Diamond and Pearl begin the fourth generation of Pokemon games they bring in 107 new Pokemon which brings us to a total of 493 Pokemon. With a total of 493 Pokemon over 400 Pokemon can be obtained in your version of Pearl or Diamond, making this the biggest Pokemon game so far.
If you're a hardcore Pokemon fan that played such Pokemon games as Ruby, Sapphaire, Emerald, Firered, and Leafgreen you can transfer your old Pokemon teams into your new Diamond or Pearl version. This eliminates the old hassle of losing old reliable Pokemon teams.
With lots of new features Pokemon Pearl and Diamond also has some old ones that weren't available in past games. One of the old features that has come back is the night and day feature from Pokemon silver, crystal, and gold. Anither feature that has been absent from Pokemon Fire Red and Leaf Green is the Pokemon Contests. However Pokemon Contests in Diamon and Pearl are motified and different. They now consist of a Visual Judgment, in which you actually dress up your Pokemon. A Dance Judgment, where you use the DS touchscreen to control how your Pokemon dances. And finally comes the Performance Judgment, which is exactly the same as the main part of the contest in Pokemon Ruby, and Pokemon Sapphire.
Just like the previous Pokemon games Pokemon Pearl and Pokemon Diamond introduce a new evil team bent on world domination. In these two games that team is Team Galaxy. Through out the course of the game you will have to stop their evil plans on your own. However you will get the opportunity to capture one of the two legendary Pokemon Dialga or Palkia depending on your Pokemon version.
With tons of new features and a lot of old ones Pokemon Pearl and Pokemon Diamond are games that every Pokemon fan should own.