What is a good fuel ?

A good fuel is one which has the following properties :

1. It should be fairly cheap and easily available.
2. Its ignition temperature should be above normal temperature.
3. It should be easy to handle and transport.
4. It should not produce any poisonous material during burning and after burning it should not leave any residue or ash behind.
5. Its combustion rate should be steady and controllable.
6. It should have high calorific value so that it produces a high amount of energy for each unit of mass or volume.