If you are really into it, don’t just use the JPGs that your camera produces, but take the literally raw output of the sensors and process it yourself. You get a lot more depth as JPGs support 8-bit color while most modern cameras actually take 12-14 bits color, so that translates into 1 stop more of light and detail. Plus, you can correct for optical distortions and so forth. There are lots of reviews, but according to twin-pixels.com, the top two are Lightroom for all around and if you are a true optical nerd, use DxO (actually, use DxO for everything but use Noise Ninja for noise reduction is the best combination, but the workflow is complicated because Noise Ninja is a Photoshop plug-in, so you need to DxO and then load into Photoshop for the noise reduction step).
DxO is incredibly complicated, but if you want the most natural picture, choose the amazingly well named preset, “DxO default v2 – Neutral colors (RAW only)”, the result will be less artificially punchy than comes out of most cameras (which really turn up the saturation). I also normally use the Neutral Picture Style on my Canon 5D Mark II for the same reason, less punch but more real.