I have always loved sitting in a bright alcove eating breakfast and reading the paper. These days the object in front of me is often an ipad or other electronics, but the wonderful feeling of a breakfast nook is always the same. Of course bays which have windows on three sides are going to be the brightest. Depending on the orientation of the house, the sunlight streaming in can be dramatic. If there are some interesting views, that is a big bonus.
Perhaps the best part is the fact that they are usually connected to the kitchen which keeps you in the thick of things. So wheather you are typing on a laptop or reading the Sunday paper, a breakfast bay is the place to be any time of day.