If you can do a little Japanese, you can buy to yourself the Japanese games of the fifth generation for the Nintendo Ds, called Pokémon White and Pokémon Black. Both contain only new Pokémon and are to be recommended absolutely on account of the new crazy graphic arts, by the new cool Pokémon sometimes seen, but if you are no so the special fan of the new Pokémon and/or you can't speak Japanese, I would advise you rather first Heartgold or Soulsilver. In my opinion.
Ps: Sorry if my English here so bad, thats all because my English is very bad and in the school we learning now the vocubalary because I'm a german kid. That's why my English is soo bad, and because I wont to sleep right now. Thank you for the Understanding. And sorry again. The half of the text is wrong, right?
~ Surando.