Where does Gothic end and Noir begin? I have no clue.
But there are similarities. In noir, cities are gloomy and politicians and police are corrupt; in Gothic, castles are gloomy and aristocrats evil. Both have dark and stormy nights lending an atmosphere of foreboding; protagonists up against superior forces; and either may incorporate, or not, the supernatural.
Anyway, here are 32 paired novels (if you like the odd number, you might like the even number after it; or vice versa) all Gothic or Noir to some degree. Of titles here, some are well-known and some not, some are old and some new, some have literary credentials and some are pulp, some have elements of mystery or the supernatural or both, one book for each day of October plus one, all dark reading for days of waning light, greying skies and bushels of leaves underfoot. Mysteries, fantasy, s.f., horror, and even a few short story collections.