George H.W. Bush (Dana Carvey)
When more people remember a president via his portrayal on SNL than his real-life persona, you know you’ve done a good job. Carvey's Bush 41 was a collection of tics and mannerisms that overshadowed the real figure – it eventually became the de facto way millions of people saw the leader of the free world. By the time the President started using the comedian's catch phrases as an act of self-deprecation, it had the uncanny effect of sounding as if Bush was doing a bad impression of himself. That's how potent Carvey’s performance was.