I love sweet potatoes and yams. It makes for a nice, light lunch.
I wash it really well and poke a few holes into it with a fork and microwave it (depending on the size) for 5-8 minutes. Sometimes I'll put a small bit of butter on before I eat it, but mostly I just sprinkle on a little salt and that's it. High in beta carotene and low in calories.
I prefer the orange ones much more than the yellow.