Actually, it is the wing loading that dictates how susceptible an airplane is to turbulence. Wing loading is the weight of the airplane divided by the wing area and in British units is measured in pounds per square foot. The higher the wing loading, the less susceptible the airplane is to turbulence. Wing span may also have some effect, because airliners are built with some flex in the wing and that flexing can also alleviate some of the jostling you can get from turbulence.
The Concorde has a much higher wing loading than any other airliner, so it is the least susceptible to turbulence.