One of the most supported medications for OCD is the tricyclic clomipramine (Anafranil).
It is one of the few drugs that have been approved specifically as a treatment for OCD instead of anxiety in general, and it has the most research support for any drug on the market related to the treatment of OCD.
Other tricyclics that may be used for OCD are amitriptyline (Elavil), trazodone (Desyrel), and buspirone (Buspar).