And yes, Gee's What Video Games Have to Teach Us... is a must read. If you like Gee's stuff, you'll also like Sasha Barab's work (more scholarly, not for the faint hearted).
I'd also recommend Cult of the Amateur - it will certainly get you thinking. We've been getting together in Second Life to discuss it. I'll make sure future meetings are posted on our EBW calendar (coming soon).