Nintendo DSIn the 16 years that the Nintendo Game Boy was at market (and that's before the GBA) the console managed to sell 119 Million Units. That's roughly 7.5 million units each year - pretty impressive for one of the first portable gaming systems!

In comparison the Game Boy Advance managed 81 million (~13.5 million / year) units between it's launch in 2001 and today.

The DS? According to DSFanboy in the three years since release the Nintendo DS has sold 50 (~17 million / year) million units - well on par to surpass both of it's predecessors.

For a closer look at console sales numbers check out the Wikipedia's List of Best-Selling Game Consoles.