It's been four years since I received what is probably the best handheld system of all time, the Nintendo DS.  My original DS was the red one that came packed in with Mario Kart DS.  Even though I was obsessed with Mario Kart on the GBA, I only played it on the DS once.  No explanation for that one.

I love this system because it's truly a portable fan's dream, not to mention all the awesome and innovative games available for it.  The best feature of the DS is that you simply close it to put it in standby and open it to start playing right away.  It's like a laptop but works super fast and never fails to come back.  Battery life can last for days with it in standby meaning you can close it up at night and then resume right away in the morning.  There has been many-a-time where I fell asleep playing the latest Ace Attorney game in bed, and the DS fell to the ground and closed on itself.  No need to even save the game!