Lamotrigine
"I have been on Lamotrigine for 3 months for treatment on Rapid Cycling Bipolar II.  I'm currently on 150 mg. This medicine has been amazing.  I tried Wellbutrin - which made me full of rage and even violent and Abilify - which made me excessively more impulsive (gambling, drinking, smoking - all of which I would normally not do).
Lamotrigine has been a God-send.  The cycling has slowed to a near halt.  I have a few mild down cycles, but they are few and far between and subside quickly.  I have been able to concentrate better.  It has even had the pleasant side-effect of helping to reduce my anxiety. The only negative side effects for me are nausea for the first few days and intense headaches for the first week after increased dosages."