Breakfast is important. However, animals actually work for their food by foraging and/or hunting, so I am not sure I buy into eating breakfast right away.
I can not say I am sure about best meal, but I always have fruit, usually fresh, with every meal. Water is critical with every meal as well. It hydrates and flushes your system and can get you alert in the morning if cold.
Protein will supply the building blocks ripped away by activity, even for the sedentary. "Safe fats", in moderation, provide your store of long term fuel; sugars, preferably from foods rather than spoons, (again, in moderation) provide your immediate energy.
In short, the best breakfast is one you research and design, one that does not impair longevity because it is solely based on flavor.
A "good ahead and kill me, but I want me goodies" attitude may seem empowering and heroic, but decline with age can be more, or less, miserable depending on your choices.
There is no "go ahead and take me, I'm ready for heaven" switch at the end. There is only decline, quick and miserable, or slow and enriching.