I've been using original formula mane & tail shampoo & conditioner. I lather up my hair twice, making sure to massage my scalp with it, and I let the conditioner sit for a couple minutes while I wash the rest of my body.
I used to use head & shoulders but funnily enough my dandruff cleared up when I switched to Kirkland shampoo (also a decent shampoo but I prefer mane & tail)