Canon 1Ds Mark III
The image quality achievable from the 1Ds Mk III, when coupled with excellent optics, is, quite frankly, awesome.
Still, for image quality and fine detail (at ISO 100 to 1600) that rivals or exceeds that of many medium-format systems, the EOS-1Ds Mark III is the only DSLR in its class.
After shooting with the camera with a few days under numerous conditions I can confidently say the Canon 1Ds Mark III is easily the most versatile full frame digital SLR currently available.
Undoubtedly pricey, certainly not perfect, but the EOS-1Ds Mark III is good as it gets, and for many users will offer a genuine, viable alternative to a medium format digital system.
I never wanted a 1Ds. Now I do.
The 1Ds Mark III marks another high-end success for Canon, though you'll need a lot of spare cash if you want to own this ground-breaking camera.