Which camera brand. Nikon or Canon?

Which camera brand do you prefer and which would you suggest to a fellow photographer? Choose between Nikon and Canon.

Compare and the contrast the quality, price, durability, efficiency, etc of each brands cameras.

I'm getting a Christmas present for a family member who is a professional photographer but I can't choose which brand.

Nikon? Or Canon?
>>> Which camera brand. Nikon or Canon?