I live in the desert where yucca plants are plentiful. I've tried it in soap and didn't notice any difference. It makes for some nice label appeal though.
Depending whether you like woody, floral or spicy, here are some good ones: Sensuous Sandalwood, White Tea & Ginger, Energy, Yuzu and Almond. Moroccan Mint is nice too.
They are well known, so they can get away with it and people do buy. I find their shampoo overpriced too. I looked at the ingredients and I can make mine better.