I was going to say I prefer my riffs on ranch, but I think what I end up with is maybe closer to green goddess in the end! Though no tarragon or anchovy so far. I think buttermilk is essential for me.
Ages ago I started buying the HVR ranch mix (the powder) in large format canisters. I use it more as a base than following the directions -- I will often blend in some combination of herbs, scallions, and (green) hot peppers, plus citrus juice or vinegar, and a glug of olive oil to balance it out. I tend to also reduce the mayonnaise in mine in favor of dairy -- often 1/3 each mayo, sour cream, and buttermilk.
Another variation I love that I stumbled on entirely by accident is za'atar ranch -- ranch made more or less "by the book" with a large quantity of good za'atar in it. Probably a quarter cup of za'atar in a batch of dressing. (I tend to prefer the za'atar I get at middle eastern grocers in large sizes -- 1lb bags or canisters – and typically labeled either "green" or "lebanese." I got some from Penzeys once and it was terrible.)
