Silk Elements Megasilk Moisture Treatment: that's the one I buy from Sally's. A few years ago, I just happened to see it, dump some oil in it, and used it for the very first time as a deep conditioner. It seems as if my hair texture changed from type 4 to type 3. I was really impressed. This is one of my conditioner staples.
Plus, I buy the Elasta QP Conditioner (which I haven't used yet) and the Soy Oyl conditioner (I haven't used this one yet either).