I like them in specialty tacos. I made a version of these with swiss chard and they were really good
http://www.marthastewart.com/349043/beans-and-greens-tacos-goat-cheese
And believe it or not, just sauteed nicely with a little salt is good.
Or one of my favorite ways is a standard Italian method, works with any of the milder, more tender greens (remove ribs from kale or chard though), saute a little onion and garlic in olive oil, when the onions are translucent, add a few pine nuts and toast in the pan, then add your greens (still wet from being rinsed). Toss in the pan until wilted. Turn off the heat and add a little goat cheese or feta or ricotta and mix. You can also add raisins, but if you do, put the raisins in some water and microwave for 30 seconds so they get plump. Super yummy.