There are a lot of medications for bipolar, both on and off label, and how well they work is really individual. First choices depend on which type of bipolar you have (I, II, NOS, cyclothymia) and what your main symptoms are. For instance, if you have psychosis with your episodes, and atypical antipsychotic might be a good place to start, but most of them can cause weight gain. Geodon is the exception, being weight neutral (and Abilify is almost as good apparently from the weight standpoint).