There's been studies that prove that each camera manufacturer's propietary RAW converters work best with each manufacturer's cameras and images. So for me, it's Nikon Capture NX and Olympus Master.

I use various tools, depending the application need. I do not subscribe to the view the manufacturer's camera raw software works the best, and have definitely found evidence contrary that that view. The following comments apply to the Mac OS X or Linux platform; I do not use the obsolete bloatware legacy operating system Windows, so I have no comment to offer there.

For simple things, or a small number of photos, the Mac OS X Preview works very well. I will sometimes do this same thing with Aperture 2.

For generic batch processing, mostly for shows, I use Raw Developer, or I use Noise Ninja. I have 2 licences for Raw Developer, both on Mac OS X. I have 4 licenses for Noise Ninja, 2 on Mac OS X, 2 on Linux. I have multiple licenses, in order to allow concurrent processing using multiple computers. I like the batch adjustment capability and the general user interface of Raw Developer, whereas I like Noise Ninja for high ISO show photos that need no level adjustment. The choice is generally guided by the type of lighting at the particular show. If the lighting is underwhelming, and I have to make up the image signal-to-noise with underexposure in camera raw, Raw Developer is more useful for dealing with that situation. If the show is modestly well-lighted (in terms of luminosity for exposure, not color as such), then I will batch with Noise Ninja for high ISO photos that need no level adjustment.

For studio work, or critical applications like for-print in magazines or posters, I will use DxO Optics. This is an application that directly refutes the contention that the manufacturer's camera raw processor is better. DxO Optics does things that cannot be done by the manufacture's camera raw software, including (automatically doing) corrections for lens aberrations using computational means. It also has an extremely clean noise reduction engine, AND can do batch processing. DxO Optics is incredible, it really adds enormous value for the very best image quality.

At the same time, if I wish to have alternative levels, or have exposure problems to fix in my studio photos, Adobe Camera Raw (ACR) is an enormously powerful tool, esp. for specific detailed exposure problems that just don't show up while chimping with the camera LCD while in the studio. I will also use this tool to perform precise creative color shifts of the image.

If there are specific tonal ranges I want to modify, or to use certain post-processing skin-tone effects early in the workflow, then I will use LightZone as the camera raw converter. This tool tends to be used more later in the workflow, after conversion with DxO Optics, or ACR; but in certain instances, it can be more effective to start with LightZone.

These are illustrative examples from my own personal workflow, I think tending to emphasize the relative strength or capabilities of specific tools. So, I should offer my standard disclaimer: your mileage may vary, destination taxes and dealer preparation fees may not be included in sticker shock.

Blessings and Light,
M