Because of a hormone imbalance, I've always had problems with varying degrees of acne. When I very first started seeing a dermatologist, he banned me from using any cleansers other than Dove soap, and it did seem to help some. It at least keeps my face from being stripped of moisture. I still use it!
A derm can put you on several meds that will help, too--antibiotics, Retin-A, or even Accutane (but it causes SEVERE birth defects, so that's a real last resort!) I also find that getting some sun on my face helps when I'm having a breakout, but we all know that can be bad long-term.
Good ol' Oxy 10 works great, too!