It varies for me. Some days I do a high protein, salty breakfast with eggs. Other days, I do a sweeter meal-replacement shake. I like to vary it up a bit.
I used to love sweet breakfasts, but then I realized that they have a lot of sugar, and it's the breakfast with complex carbohydrates that gives more energy. And sweet breakfasts are too simple, they make me hungry.
A balanced breakfast should include all the nutrients your body requires, and a salty meal is typically more satisfying than a sweet one. A salty breakfast has numerous advantages that are quantified in terms of health and satiety power.