On 30 April 2011, President Obama addressed the White House Correspondents Dinner.
The funniest bit starts 9 minutes in, when he takes on his successor, so many years before anyone thought that would ever be a true sentence. And at 12:45, roasts the 46th president, even more years before anyone expected that to happen.
And he's really funny:
Oh, one other thing. Don't forget that the next evening (Washington time), the US Navy killed Osama bin Laden, for which Obama took complete responsibility—as he would have done had the raid failed. Which Obama had ordered just a couple hours before attending the dinner.
After that, watch his roast from 2015 for another dozen laughs. Man, I miss him.