Hi. In case you've not already seen it, Niklas Frykholm of Autodesk recently did a walkthrough of all of the core engine systems of the Stingray engine (formerly the BitSquid engine). You can watch them all on YouTube here
. I found them really interesting, and I think the team's development philosophy seems quite 'handmade' in many ways. Certainly seeing how the engine is designed made me much keener to try it.
Also his colleague Tobias is writing a walkthrough of the rendering code
, although I've not had a chance to read those yet.
Anyhow I thought these might be of interest to people, since they focus on sane modern game engine implementation techniques.