Oops, not Nealon, Hartmann:

http://snltranscripts.jt.org/90/90mmetrocard.phtml

Since it doesn't include the Roseanne/Kevin Nealon "Metrocard" commercial from SNL 1991, then it isn't the 50 greatest.

Mr Show is friggin brilliant, I'm so glad to see it getting some love. Apart from great sketches, the way they structured the entire show, by having sketches flow into each other in entirely unforeseen ways, was really unusual and often jaw-dropping in its creativity.