SHEC-Labs has produced a fun, online web-based fuel energy value calculator that converts between quantities (either by volume or by mass) of various fuels based on energy equivalence. 

The calculator gives you relative comparisons, not the actual Btu per gallon or MJ per kilogram of a particular fuel. For example, you can see that a gallon of diesel has 26.4 times the fuel energy of a gallon of compressed hydrogen, but a kilogram of that diesel has 0.32 times the energy of a kilogram of hydrogen.

It includes ethanol and some gaseous fuels, but no synthetics.

SHEC-Labs is a research and development company working on the solar thermal-catalytic production of hydrogen. (Earlier post.)