I like kale because of its body--it's got a good pushback when you're chewing. And I cook a lot of spinach, using a very simple recipe I learned in Japan. Chard I used to cook when I grew it myself. In the second group, I cook most often beet greens; I like them a whole lot. But mustard greens are a good second, and I like this idea of curried mustard greens and kidney beans--must try that! And a friend over on the LJ side of things had a good idea for cooking turnip greens.