The speed from A to B with the least fuel burn would be best "specific range". It is significantly faster than best L/D. It is the speed on the peak of the specific range curve. LRC is 1% faster than that. "Specific range" is the speed to fly (no wind) when you want to convert fuel to MILES.
L/D max is the speed to fly if you want to convert the fuel to HOURS and MINUTES. It's also known as Max Endurance and most operaters use this (+ or - a few knots) as HOLDING speed.
Least fuel flow (due to varying efficiencies of jet engines) is even slightly slower than L/D max. It is a very unstable speed (due to the angle of attack) and really has no practical application.
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