If you mean the most energy per unit weight of the fuel, this is uranium at present. In the future if nuclear fusion can be made to work, this will provide even more per unit weight (by unit weight I mean per gram or kilogram).
On the other hand if you mean the most total energy as used world wide, this must be oil, as it is used so widely in transport. In terms of electricity coal is still the largest single provider of electric energy.
You can see that in posing such a question you need to be more precise. What does 'most' mean, and what types of energy do you include?
Simple sugars are used for immediate energy conversion in most living things.
Cells use ATP (adenosine triphosphate) as their immediate energy source.
glucose
If cells do not have immediate energy needs, they can convert glucose to glycogen for storage in the liver and muscles until it is needed. This stored glycogen can be broken down into glucose when the cells require energy.
IgM immunoglobulin class reacts best at room temperature for immediate spin testing.
Carbohydrates are the body's primary and immediate source of energy.
Carbohydrates usually provide immediate energy to the body.
Simple sugars are used for immediate energy conversion in most living things.
Cells use ATP (adenosine triphosphate) as their immediate energy source.
Adenosine triphosphate (ATP) provides energy for immediate cellular work.
Carbohydrates are the body's primary and immediate source of energy.
energy expendature > energy intake. there is no super secret way to lose weight and this is pretty much the only option.
The use of force to prevent an attack in a situation where immediate action is the only possible option
glucose
Glycogen
Tidal and wave energy is best suited for generating electricity, which will then power just about every device on earth. Flour mills powered by paddle wheels in rivers were the only other immediate use of water energy in the past.
A high-quality rubber weather strip is the best option for under the door to prevent drafts and improve energy efficiency.