I always make my own salad dressings, and buttermilk ranch dressing is one of the favorites that I enjoy . Blue cheese dressing also has buttermilk in it, as well as mayonnaise and the blue cheese.
My mom first acquainted me with buttermilk when I was a child, and I have liked it ever since. As has been mentioned, it is great in many recipes , and I especially like buttermilk in corn bread and also in pancakes.
If you take about one-third cup of buttermilk and add it to regular milk in a quart jar, and then let it sit out overnight, the next day it will have cultured into a quart of buttermilk.
I also make kefir, which tastes similar to buttermilk, and can be used in place of buttermilk in most recipes. Since kefir has even more of the good probiotics than either buttermilk or yogurt, this is what I usually use instead of buttermilk.