What Is the Best Color Space to Work with for Hand Detection: RGB, HSV, or YCrCb?
Intuitively, HSV is the place to easily define Skin Color Hues.

Yet there is a broad work on that and even articles about the optimal Color Space for Skin Detection.

Yet, you should have a look at OPTIMUM COLOR SPACES FOR SKIN DETECTION (Alternative at IEEE - Optimum color spaces for skin detection).

According to them there is no difference in the performance as long as you create the Optimal Detector.
This actually makes sense, since all Color Spaces in the article are One to One functions it means the real thing here is to develop the correct classifier.