I have horribly dry skin in the winter and absolutely HAVE to use moisturizer - My favorite for acne prone skin is the Proactiv moisturizer- extremely lightweight, I wear it under makeup and you can't tell, it's not greasy AT ALL, and it has spf in it.
Nutrogena Rapid Clear Acne Defence Lotion... it is a light, plesant moisturiser, with 2% salicylic acid to help unplug blocked poresand prevent acne lesions from forming.... I buy it online from Amcerica because it isnt sold here in Australia any more... its woth the cost and inconvenience to still get it