Depends upon the view, the traffic, the climate, the floor plan, and so on.
I'm in WI, for example and I LOVE my four season's sunroom on the south side of the house, because the outside temp. can be -20 with piles of snow outside, but if it's sunny, the room is still toasty. And the homes across the street all have the house oriented so the back faces east. Why? Because they want to take advantage of the view overlooking Lake Michigan. My point? There are many factors to consider and no one right answer.