The average molecular orientation at the solid substrate, measured by the orientation order parameter s sub , shows excellent universal scaling with the free energy difference defined by eqn (3) for the entire range of systems studied, covering temperatures from 0.56 to 0.84ε/k B , bulk volume fractions from 0.29 to 0.50, strongly and weakly interacting substrates, and shape and interaction anisotropies corresponding to molecules as varied as benzene, perylene, and porphine (Fig. ; see ESI Table for a full list of systems). Interestingly, although systems with a predominantly side-on orientation at the solid interface are observed, they are relatively rare, being obtained in less than 15% of cases. These side-on systems generally correspond to situations for which the fluid particles have low shape anisotropy (high κ), the system is at low temperature, and to a lesser extent the fluid particles have high interaction anisotropy (low κ ). The rarity of the side-on orientation points to a dominant entropic contribution in most systems studied.