I like my street scenes to be busy, composition wise. I like to be able to go back and look at the scene and see many different things happening, rather than just one focal point. It can make the compositions busy from a technical standpoint, but I often break that rule in street photography. I like to approach it from a "Where's Waldo" standpoint and see how many things you can see in one scene.
I especially like night photography and peering into shop windows to see the activity.