This infamous SNL skit parodying 1990s R&B bands is far and away the best thing he’s ever done.
I’m not sure I understand the logic behind using it to promote Barack Obama, though.
Update: Apparently, the Obama campaign had a stroke of genius and realized that “Dick in a Box” may not have been the greatest way to promote their candidate (the embedded video was from the official Obama 2008 YouTube station, believe it or not). It’s been pulled. To make up for it, here’s a link to the uncensored original (with short commercial intro). I can’t embed it, since it’s at Hulu, but also since it’s Hulu, it looks and sounds much better than YouTube.