Bill Murray returns for David Letterman’s 20th anniversary on CBS tonight

Bill Murray returns for David Letterman’s 20th anniversary on CBS tonight, a mark that will make the late night host’s fans feel both nostalgic and, quite frankly, a little old.

Murray was the first guest when Late Show With David Letterman made its highly publicized move to CBS on August 30, 1993, and the two will reunite tonight at 11:35pm ET to mark the 20th anniversary. It will be the comedian’s 26th appearance on Letterman’s show, which doesn’t include his visits to the host’s previous stint at NBC (where Murray was also his first guest).

Tonight’s milestone is one that many never would have envisioned 20 years ago, because Letterman at the time seemed destined to forever reside at NBC — where he made his debut in 1982 with Late Night with David Letterman. Airing nightly after The Tonight Show Starring Johnny Carson, Late Night provided a vehicle for younger viewers who were drawn to his irreverent humor and staples like Top 10 lists, Stupid Pet Tricks and Stupid Human Tricks.

Antics like that are fairly commonplace in today’s cluttered talk show environment, but Letterman created a niche that catered to a younger audience — including college students like myself at the time. We all gathered around to see him what he would try next, which included everything from dropping watermelons off a roof to being lowered into a tank of water with a suit made of Alka Seltzer.

When Carson retired in 1992, many assumed Letterman would naturally move up an hour to fill the coveted slot. NBC, however, opted for Jay Leno, prompting a defeated Letterman to take his show down the road to the Ed Sullivan Theater. Twenty years later, he is celebrating his anniversary on CBS, where he has broadcast 3,897 episodes and four primetime specials. In addition to receiving nine Emmy Awards and 73 nominations, Letterman was a recipient at last year’s prestigious Kennedy Center Honors.

While heaping praise on Letterman is surely due, there have been some noted missteps along the way — including a mean-spirited joke about Sarah Palin’s daughter, an affair with a staff member that led to a highly-publicized blackmail attempt, and claims that he has allowed his political views to dominate his show.

There’s no question that David Letterman has lost a step or two over the last 30 years (who hasn’t?), but he has made me and millions of others laugh on many, many occasions. It is my honest belief that Jimmy Fallon, Jimmy Kimmel and Conan O’Brien would not have their shows today had he not blazed the trail.

Strange as it may seem, my greatest memory of Letterman has nothing to do with a joke, a list, a stunt or a comedy bit. A few days after New York City was attacked on September 11, 2001, Letterman sat at his desk and offered an unscripted speech from the heart. The man who has made a career out of being divisive for one night brought us all together at a time when we needed it the most.

Pictured: Bill Murray during a 2010 appearance on Late Show With David Letterman. © 2010 CBS Broadcasting Inc. All Rights Reserved. Credit John Paul Filo