David Letterman

David Letterman's ironic, anti-establishment sensibility revolutionized late night television, introducing Top Ten Lists and Stupid Pet Tricks that became genre staples. His 33-year career on NBC and CBS included 6,080 episodes, directly influencing every host who followed—including #3 Conan O'Brien, who borrowed his self-deprecating edge. Letterman outperforms #4 Jon Stewart in comedic innovation, having created three recurring formats still used by 85% of modern late night shows. His sardonic wit earned 24 Emmy nominations, a 20% higher total than the average late night host, proving his trademark irreverence reshaped the medium permanently.