Anything to do with xbox/psp - ds loves getting microsoft points
Remote control car or similar - I got my son a sphero which you control with an iPad - its fab.
Book set - can't go wrong with Harry Potter and anything by Antony Horowitz is normally good - my eldest ds especially loved the Alex Rider series at this age and dd's class (also 10) are doing the whole series as their school reading.
Lego - although mine don't play with so much now.