What is the best digital camera?

The best camera is the one that captures the pictures you want to take.

If you are often mobile and active a sports camera that is sturdy and has good weather/shock protection is great. If you are a studio photographer who takes images of still objects or insides of buildings and you need a great amount of detail a larger format camera is good (there are some VERY expensive cameras made that have fantastic abilities for example the Sinar)