We perform a comparison of electron affinities (EA) of the conjugated molecules bithiophene, azulene, naphthalene, and their water clusters. Bithiophene and azulene monomers have positive EAs of +49+/-5 meV and +790+/-8 meV, but naphthalene has a negative EA. Despite their different EAs and their different molecular orbital energies the three molecules show very similar microsolvation shifts per water unit. This is explained by similar sizes of the pi orbitals in which the surplus electron is delocalized leading to a similar electrostatic water to charge interaction. This qualitative dependence of solvation energy on anion size agrees well with classical solvation concepts. A comparison of our binding energies with previous calculations for other systems shows that formation of a water subcluster can be assumed. For all three molecules the cluster EAs increase nearly linearly with the number of waters. Using a linear approach and a calibration for the error in the first solvation step we extrapolated the naphthalene (H2O)(n) cluster series to a monomer EA-200 meV+/-50 meV, in good agreement to previous measurements. To become new insights B3LYP/6-31++G** structures and energies have been calculated fur azulene, naphthalene, and their clusters with one water and compared with experimental EAs.