The Nintendo DS is my absolute favourite handheld gaming system, it's way better than it's contenders and sales show just that!
The dual screen with a touch screen is great, and it has backwards compatibility with Gameboy Advance games, which I have quite a few of from my younger years. The R4 card technology makes its memory base endlessly expandable, and you can download games right from the digital online store.
Now we have the 3DS, and only time will tell whether or not Nintendo whittles out the more traditional 2D Nintendo DS models and only produces models with 3D capabilities from now on.
My favourite games at the moment are Super Mario Brothers, Animal Crossing, Sonic Rush and Pokemon Pearl. I do enjoy a bit of brain training too but only on my morning commute, I'm much too exhausted for that on my way home!
Photo: Dan Dickinson (Flickr)