Finally traded in some duff Xbox games and got a new one: "Lego Star Wars". Brilliant game for the kids. The problem I find with Xbox is that there are tons of games for older kids and adults but very few games for younger kids. PlayStation and Nintendo are better in that regards. Lego Stars Wars looks great and has fabulously simple game control. Killing just involves breaking apart lego opponents so the violence it tame enough. It's even fun as an adult. Recommended.
However, beware of buying the PC version. You might get a "Pixel Shader 1.1 Required" error. I spent some time trying to fix this for a friend only to discover the real problem is that the graphics card/chipset must support hardware transform and lighting (T&L). This precludes onboard Intel graphics chipsets and means you need a half-decent graphic card that supports DirectX 9.0c. For those on a limited budget, I'd recommend a Radeon 9600XT or at least a Radeon 9600.