Actually, I'm a teacher - currently teaching music in Beijing, but starting my MA in Gifted Ed in January.
As for recommendations, I'd have to say your son is in the right place with RPGs. Online RPGs can get repetitive and boring, especially if you're not drawn by the social element, but traditional offline RPGs are known for their strong and thoughtful stories. I'm not sure about what would be appropriate for your son - video game ratings aren't that useful to start with, but gifted kids mature at their own pace, so I'd suggest you read reviews or ESRB pages on some of these and see what you think. That said, check out something from developer/writer Ragnar Tornquist. "The Longest Journey" and "Dreamfall", which I loved, are probably too mature for your son (no violence but plenty of bad language), but "Syberia" might be okay. The development company Bioware is THE name in single-player RPGs these days; Star Wars: Knights of the Old Republic is great, and not just for fans of the franchise. The aging Myst and Monkey Island series are classics, though I'll admit I've never played either myself. Monkey Island is very much a kid's game, and might be too simple for a gifted eight-year-old.
For games a bit more "out there" in concept and execution, try the ones mentioned in
this article - World of Goo, Machinarium, and Braid especially.
