With 25 organic molecules that represent popular functional groups, we tested the transferability of force field parameters using both parametrized force fields CHARMM, CFF, and MMFF and generic force fields DREIDING and UNIVERSAL. We found that, if transferred parameters are used in a parametrized force field, the calculation quality is no longer superior to that of a generic force field. To achieve high quality in predictions, new parameters should be created from ab initio data whenever necessary. We investigated this approach and found that a custom-built force field can be made to reproduce ab initio results if parameters are derived specifically for the molecules of interest. The parametrization procedure was applied to a group of classic antibacterial drug molecules, the sulfonamides.