Dir en grey - The Marrow of a Bone
Obviously not everyones favourite music (or production), but sounds pretty damn good and organic to my ears. I'm pretty sure Kaoru (left channel) is using a VH4, and it's so nice and crunchy. The new album sounds like it's double tracked as well. The older stuff is probably double tracked too (at least Vulgar and Withering to Death are), but their production is horrible.
Ion Dissonance - Minus the Herd
I'm not actually sure if this is double tracked, I was listening to it yesterday and I decided that it sounds like it was double tracked. Then again, the guitarists are probably so tight that you wouldn't notice the layering. Again, not everyone's favourite (most prefer Solace) but I think the production is just awesome.
Ihsahn - both solo albums
The production is not that awesome, but still pretty organic and a nice change.
Tool - All albums
Not even double tracked, just a guitar plugged into 3 amps.