When my guys were that age anything sports related would have been just the thing.
DGS is that age and anything related to Nascar is his current thing. Prior to this it has been construction equipment, Pokemon, Cars/Cars2, Toy Story, anything yellow (during the construction equipment era), changes fairly quickly with him. Oh he also really likes penguins right now too.
So I will second the advice to find out what he likes, both subject and color(s). That can make a big difference to kids that age. . .more so than with younger or older a lot of times.