my son is obsessed with his . He has had it for about four years now and they are excellent for taking out to a meal with you with headphones in, keeps them occupied you see loads of kids in restaurants with them .
I have to say the lego type games, the mario type as well are good and he has some sims ones.
For xmas I got some cheap in toys ru s about 4 pounds each and some of them were book type ones that he could read on his d.s. - I live in hope he will one day enjoy reading lol!!!
Supermarkets such as asda and sainsburys often have them cheap also amazon