After watching The Oprah Winfrey Show today and hearing her teary announcement about her decision to end her syndicated talk show, I had one thought in my head. Oprah Winfrey is doing a Johnny Carson. She's writing her own script (no pun intended). Oprah is leaving while she's still wanted, while she's still strong, and by setting the date 18 months down the road, she's giving herself a victory tour.

This is very much like Johnny Carson's decision to leave The Tonight Show. The difference, of course, is that Oprah's show is not an established landmark entity like The Tonight Show, which had Steve Allen and Jack Paar as hosts before Carson. No, Oprah was/is The Oprah Winfrey Show. She will not leave it behind for someone else to inherit the throne. She's taking the throne with her.

On June 23, 2009, the trademark laugh of the greatest sidekick of all time was silenced as Ed McMahon floated up to the great sidekick couch on the sky. While Publisher's Clearing House commercials and 'Star Search' reruns will never be the same, the good news is that McMahon, who rose up in the wake of some pretty stellar sidekicks himself, set the bar high for those to follow.

Perhaps he set it too high, though, as newcomers to the talk show field like Jimmy Fallon and Craig Ferguson have chosen to fly solo on their talk shows. And that's a shame. Like wine in a box and BBC America series, these straight men of the chat circuit are all too often underappreciated and overshadowed but consistently, inconspicuously deliver the goods.

'The Tonight Show' has been a late-night institution for more than 50 years (yes, that's right -- half a century).

Jack Paar, who took over the reins from Steve Allen in '57, put the show on the map, with big-name guests and outspoken antics. Johnny Carson, who stepped in when Paar left, made the show appointment viewing for millions of fans and became one of the most beloved TV hosts of all time.

Now, with Jay Leno's last 'Tonight Show' airing Fri., May 29, and Conan O'Brien taking the desk while Leno makes the unprecedented move to prime time, to a 10 PM slot in the fall, we look back and count down the top 20 moments of 'The Tonight Show.'