My ds1 is 9 in a couple of weeks and Pokemon potty! He is desperate for either Black or White for his birthday and has persuaded his little brother to ask for a DS and the other one for his birthday the week afterwards. 
He's only allowed a hour a day on his Nintendo and very often when he's not on the DS he can usually be found scouring the Pokedex and game guides.
I'm currently motivating him to do his spellings and handwriting exercises by allowing him to choose a different pokemon sticker at the end of every session. (Ebay have hundreds of them really cheap and he loves the ones we have at the moment, because they have all the pokemons in lots of different stages of evolution - apparently.)
He used to be obsessed with the Zelda series, but they don't bring new ones out often enough, so whilst it still has a special place in his heart, he pretty much switched allegiance to Pokemon.
He also loves Mario - although I have to admit to switching off slightly
so am not too sure which game/s or why he likes it.
I wonder what it is about Pokemon that grabs them all so much?
Oh and other than DS games, he is currently reading every BeastQuest book he can lay his hands on - especially the new series. They are too easy for him really - he can read a whole book in an hour, but they really seem to have captured his attention for some reason.
We are Warwickshire-ish, so not really all that close to any of you.