The Big Cheese

I've designed this to be given as a prize.

'Meaning:
The most important person.
Origin:
In earlier times the cheese didn't have to be big - 'the cheese' alone was a synonym for quality. We now use cheesy to describe anything second-rate, artificial or even smelly. Going back to the 19th century the meaning was just the opposite. 'Cheese' or 'cheesy' is listed in John Camden Hotten's The Slang Dictionary, 1863 as:

"Anything good, first-rate in quality, genuine, pleasant or advantageous"'
http://www.phrases.org.uk/meanings/64350.html