Sam Waterston as D.A. Jack McCoy and Linus Roache as A.D.A. Michael Cutter on NBC's Law & Order.
I'm going to make this guess: If you could round up a list of "at least medium-level famous actors of the last 10 years," and if we could all agree on it, Law & Order -- officially canceled as of today -- would appear on the resumes of more of the actors than any other television show. I think that has to be true, for what would seem to me to be four reasons: (1) It's been on forever; (2) It uses lots and lots of guest stars every week; (3) It filmed in New York, and therefore used a lot of people who were otherwise working in theater and therefore at least aspired to be "serious" actors; and (4) It has an eerie ability to spot stars of the future.
Okay, the fifth reason I believe this to be true is undoubtedly the availability heuristic, but let's put that aside for the moment.
I remarked on Twitter a while ago that if you see a young woman on Law & Order and she's played by someone who later became a well-known actress -- even if she wasn't then -- you should assume she's deeply troubled and her problems will become a big part of the plot.
This was true when Claire Danes, two years before My So-Called Life, played a young girl who aspired to be a model. It was true when Sarah Paulson showed up in her very first TV appearance ever. It was true when Lauren Ambrose was on the show three times between 1992 and 1998. It was true when Ellen Pompeo played the daughter of savagely attacked parents in 1996, nine years before Grey's Anatomy.
The other day, I caught one where Philip Seymour Hoffman, resembling his movie self in no way whatsoever, got his very first screen credit (according to his IMDB profile) playing a preppy rapist. His co-defendant was played by Gil Bellows, later of Ally McBeal, who was much more experienced -- he was getting his second screen credit ever.
I recently also noted on Twitter that I'd spotted Rich Sommer, who's now on Mad Men, in a brief appearance as a lab researcher. He tweeted back, "My first TV role! I was terrified and underprepared."
It goes on and on (and on), and my guess is that many of you have your favorites. Peter Facinelli as a despicable, smarmy high-school student (in an episode that also featured Aasif Mandvi in a tiny role, long before he hit The Daily Show)! Amanda Peet as a Patty Hearst-inspired kidnap victim turned maybe-criminal!
My guess is that this phenomenon contributes considerably to the way the show thrives in reruns on TNT. It's definitely one of its little pleasures to discover in just about every episode one of those people you know wasn't a big deal at the time, but is at least a moderately big deal now. As a matter of fact, you can get to the point where, if you see an important role being played by someone you haven't ever seen in anything else, you find yourself saying, "Huh. Wonder what ever happened to that guy."