Those familiar to DSLR will probably have come across discussions of which of the cameras' ISO settings to use and which to avoid. What's more important images with less noise or more dynamic range?
"There seems to be a common misconception out there, held by even some very well-regarded experts that the cameras' "native ISO" or "true ISO" settings are the multiples of 160 (ISO 160, ISO, 320, ISO 640, etc), and that the rest of the ISO settings are produced digitally. This is not true. In fact the cameras' native ISO settings (that is, the settings that are derived from analog gain rather than digital exposure compensation) are the multiples of 100 (ISO 100, ISO 200, ISO 400, ISO 800, etc). However, that doesn't necessarily make them better."
Bi-coastal DP, Josh Silfen investigates the truths and untruths about ISO settings on HD DSLRs on his Shootin The Shot website. You can read his blog in detail here.
So which is more important, shooting images with less noise, or shooting images with more dynamic range? It's obviously subjective, but for Josh there is no one-size-fits-all answer.