AHA (specifically glycolic acid) is awesome for acne, and exfoliating and wrinkles and ingrown hairs (if you're a dude). It's seriously not in enough products marketed for acne.
For that reason, my favorite daytime moisturizer is Neutrogena Healthy Skin Face Lotion w/SPF. It's the highest concentration of glycolic acid in a product I can find in the drugstore; I only wish it did not have fragrance in it. My favorite online one is the AHA Lotion that they sell at acne.org. It's has no irritating ingredients & the price is right.