Kale, spinach, cauliflower... I like them all if they're prepared properly. As hgtonyvi said, most people don't know to cook spinach or kale. Or nettle, which is a good substitute for spinach...
There's an old recipe for making good food: Take one lbs butter and a litre of cream, plus the normal amount of ingredients for four. Sauté the ingredients in the butter and add the cream.
Another good recipe is the Lappish Loon Soup, as told by the Sami huntsmen:
Take one loon. Put four litres of fresh water into a kettle. Heat to boil. Cook the loon in the water for ten minutes. Throw the water away.
Put three litres of fresh water into the kettle, add a handful of grass. Heat to boil. Cook the loon for five minutes. Throw the water away.
Put two litres of milk into the kettle. UHT, pasteurized or cow milk, whatever you have. Heat to boil. Cook the loon for one minute. Throw the milk away.
Put one litre of good clear spirit into the kettle. Let the loon simmer for a few seconds. Throw the loon away.
Enjoy the soup.