The "Tallest Midget" is when someone or something is the best at something, but that something isn't anything special. The tallest midget is the tallest one of his group - but although he is the tallest midget - he is still, at the end of the day, a midget. Also could be called the "Hottest Garbageman".
Fans of the Clemson Tigers are jubilant after their victory in the 2011 ACC Championship Game. What they fail to realize is, while they are the ACC Championship, they are still the tallest midget.