“That was a tone poem,” “thirtysomething” co-creator Ed Zwick used to say to his colleagues after a rough-cut screening, modestly describing his own episodes. They weren’t, of course. The 1980s television drama deserved its status as a classic for its groundbreaking look at baby boomer life – but it never quite felt like a tone poem, whatever that was. Still, the show Mr. Zwick (and his partner, Marshall Hershkovitz) created stands as a shining example of how far broadcast television can go when it wants to. A deeply felt family drama, “thirtysomething” caught perfectly the tenor of its time. Its themes of self-absorption and career versus family and love played out on a canvas of young, good-looking dreamers. It was great television, and if you liked great television you never missed it.

Another show has come along to join “thirtysomething” in the pantheon of great network dramas. It’s the first new one in a while. This season will properly be remembered as the first year of “Lost,” a series that reminds us why the networks still exist: to pay the exorbitant price tag that no one else can afford for shows with this kind of production value. The pilot alone cost $10 million to produce. You could never have seen “Lost” on HBO; they don’t have the bucks to send dozens of well-paid actors to Hawaii for eight months. ABC has given “Lost” a first-class and swanky production, and it shows in every frame.

But it’s the story itself that makes “Lost” so thrilling to watch each week – the Shakespearean conflicts that constantly roil this makeshift community of castaways. As each episode delivers a new flashback sequence to establish another cast member, another piece of the endless puzzle locks into place. But by the end of the hour a new puzzle has been created; somehow, even with the new information, we know less than we did before. Each week it challenges our assumptions and keeps us guessing. Even though they claim otherwise, you get the feeling that the producers are only two or three episodes ahead of us, working out the rules of this brave new world as they go along. The story has reached a thrilling stretch; in last week’s episode (cleverly titled “…in Translation”), a few characters dared to admit to one another that they actually preferred living on the island to their previous life. For the first time, the notion of a “fresh start” got explored as an appealing possibility. And at long last, two characters on “Lost” have had sex. They kept saying the week before that they’d been there a month now (surely someone on the island has been assigned to count days!), so it was bound to happen, right? And the fact that it involved Said surprised no one among the show’s devotees.

Okay, so it’s sounding like a soap opera. But so what? That was the rap against “thirtysomething,” too. If we’ve learned anything since then, it’s that soap operas are to be embraced, not shunned. Just ask Marc Cherry, the creator of “Desperate Housewives,” ABC’s other hit show, and another concept that HBO wouldn’t touch. The soap-opera notion applies to just about any serial drama on television, including reality shows, and drives just about every storyline on television except those overseen by Dick Wolf (see also under “shows, pointless”). It keeps you coming back, right? That’s hardly an underhanded motive for a series that airs every week.

It’s great that the creator of the mediocre spy drama “Alias,” J.J. Abrams, has the leftover brain power to produce something as poetic as “Lost.” Yes, that’s right, it’s a tone poem. It turns out you know one when you see one. The episode that aired last Wednesday achieved a whole new level of emotional impact, with its backstory riff about Jin’s violent past, the troubles in his marriage, and his eventual reunion with his estranged father. Those scenes were intricately intercut with present-day scenes of Jin and his wife doing battle in their new island culture; the moment when Sun discloses to Jin that she speaks English ranks among the show’s best. A final beat had Hurley (may we humbly request his backstory, please?) on the beach listening to Damien Rice’s haunting song “Delicate” until suddenly the batteries in his discman die. It was a moment both hilarious and sad, and it defined “Lost” as a show to be considered and remembered for years to come. “Lost” is the reason we need the networks to survive.

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Dick Wolf (see also under “producers, greedy”) describes his “Law & Order” shows as though they are part of the Mercedes brand of television. “You know the cars are all different, but you know it’s a good car,” Mr. Wolf told Entertainment Weekly. Metaphors like that might just prompt a critic to tell Mr. Wolf to take a look under the hood of his new series, “Law & Order: Trial by Jury.” That ain’t no Mercedes, mister.

The problems with “Trial by Jury” begin with Mr. Wolf’s decision not to scrap the first two episodes – the ones that have the late Jerry Orbach in them. To those of us who loved Orbach for a career of amazing performances (especially as Lennie Briscoe on “Law & Order”) it was painful to see how frail he looked in the last weeks before his death. Of course many will think it’s a great tribute to Orbach to allow his last performances to be seen now, but to me it feels like an exploitation of his memory to show him in the final throes of a killer cancer. The decision to leave Orbach in so colored my view of “Trial by Jury” that I probably didn’t judge it fairly. But nothing in the first three episodes suggested to me a series with any vitality or spark. It was nice to see Tony Bill, Annabella Sciorra, and Peter Coyote again, but none of their performances matched up to their best work. The premise in the pilot, that a Broadway director would strangle a chorus girl and then cover it up, seemed like a plot borrowed from the eighth season of “Columbo.”