Among HF, NH\(_3\), CH\(_4\), and HCl, HF has the strongest hydrogen bond. The reason is because the strength of a hydrogen bond depends on the electronegativity of the atom bonded to hydrogen and the size of the atom. HF's combination of the most electronegative atom and a relatively small size makes it the strongest hydrogen bond among the given molecules. Fluorine (F) is the most electronegative element, creating a large dipole moment in HF, which results in a strong hydrogen bond.