There are many veterinarians to choose from in the Cincinnati area, so it all depends on where you live. The vet I trust my pets with is Dr. Larry Smith of Salt Run Veterinary Clinic in Maineville. It's a little bit of a drive for me (I used to live a little closer), but I've been using him for years. The staff is so friendly and caring and they remember everyone's names. There are some good vets in the Hyde Park/Oakley area. The Hyde Park Veterinary Clinic is supposed to be good, as is the Cat Clinic of Cincinnati. Most PetsMart location have a Banfield Pet Hospital inside; you can find PetsMarts throughout the Cincinnati area.
There are also a number of mobile vet options: House Vets for House Pets, CatCalls, and Dr. Karen Kowalski are just a few. United Coalition for Animals offers a low-cost spay/neuter clinic. If you need emergency vet services, MedVet is centrally located on Redbank Expressway in the Oakley/Madisonville area or Cincinnati CARE Center is located in the Blue Ash/Sharonville area on Kemper Road.