As Robert said above you must first get a good exposure ion camera.
Especially avoid underexposure.
I am getting very good RAW conversions with Photoshop CS5 and the latest version of ACR
The noise reduction is very effective in ACR
I tested the latest Canon DPP but was not impressed with the noise reduction capabilities (especially luminance).
I tested Aperture v3 on but did not care for having to import into library.
