Distinctive. Memorable. And timeless.
It is aesthetically pleasing.
It is scalable, looking good while as large as a billboard or as small as a dime. It looks good in color as well as black and white. And it is simple enough that it can be applied to a media spectrum as broad as paper to plastic and t-shirts to websites.
Most importantly, a good logo communicates the unique qualities of its brand.
What do you think? Do you agree with his definition of a good logo? Do you think these are good selections for the top 20? Who would you have included?