One of the most important considerations to make when visualizating data is the complexity of your visualization.  We all want the "wow factor" in our data, but there are times when a simpler approach to visualization tells a better story. Your aim should be to inform rather than to entertain. For example, look at the increase in world food prices as visualized in Wolfram Alpha.  By using a simple line chart we can clearly see when the price of coffee has increased over the last 20 years.  With few visual elements its easy to see the price spikes in lat 1994, 1998 and 2011.  Below you will also see a collection of tables which give you the average current world price of different foods.  Here a table works just fine becaue we are comparing the price of one food item at one point in time.  It is easy to get the relative value of one item to another.