A big part of visualizing data is conveying scale and differences in magnitude. The following examples do this particularly well.
To start with, view John Burn-Murdoch's graphic on high-speed elevators for the Financial Times at http://www.ft.com/cms/s/2/1392ab72-64e2-11e4-ab2d-00144feabdc0.html.
The following screenshot doesn't really do it justice:
If the preceding screenshot were a live visualization, you would see the elevators at each building endlessly rise and fall, with a counter beneath tracking how many times the elevator has gone up and down while looking at the page. A nice bit of easing at the top and bottom makes you feel that the little magenta square travelling along the line is a real elevator, subject to physics in the same way a big metal cage rapidly moving up and down the world's tallest buildings would be. Although this printed version only communicates one dimension--the relative heights of each elevator and building--the interactive...