I was sorry to hear that the original Law & Order has been canceled by NBC just as it was about to break the record set by “Gunsmoke” as the longest-running live action television series. I can’t help feeling that there have already been so many episodes of the original and its many spin-offs that (a) at any given moment, there is one on cable somewhere and (b) no single person will ever find the time to see all of them. But cancellation of the original means that there will only be one left that is shot in New York. And for me, the greatest pleasure of the show is seeing so many fine East Coast actors. It has been many years since I have read the actor biographies in a theater program without finding at least two or three of them have listed “Law and Order” in their credits. NPR’s wonderful Monkey See blog has a post about the famous actors who appeared on the show and its offshoots early in their careers, including Philip Seymour Hoffman, Claire Danes, Amanda Peet, and Lauren Ambrose. Some of my favorites have shown up, too, including Bobby Cannavale, Samuel L. Jackson, John Ritter, Cynthia Nixon, Ludacris, and Martin Short. And I loved Michael Kinsley’s piece on Slate about the challenges of loving women who watch (but don’t necessarily love) “Law & Order.”I look forward to watching re-runs for many years and discovering early performances from more future stars. In the meantime, as the ultimate proof of the show’s impact on our culture, here’s an affectionate tribute from “Sesame Street.”