What else is there to say about “Say Anything,” the era-defining, hopelessly-romantic teen rom-dramedy that launched Cameron Crowe as a Grand Romantic Gesture filmmaker and John Cusack as a leading man?

Sitting through it the other night for perhaps the first time since it came out, certainly the first time in decades, I was bowled over by how smart, sweet and funny it still plays. The teen romances of that era, by and large, haven’t aged well, and not just because of the hair and the fashion sense.

I started my career as a critic during this “golden age” of teen rom-coms, and it was never as rosy as we tend to pretend to remember. “Say Anything…” (as it was originally titled) is aging better than any of its high school rom-com classmates. It’s the true classic of the era and of the genre.

I dial-hopped by a young Patrick Dempsey star vehicle from the era last night and was instantly bored and filled with near revulsion. Even the exceptions to the rule, the John Hughes films, have a cringey quality today, partly due to the affluence and attitudes and the bizarre version of suburban Chicago high school life that almost never showed a black face.

“Say Anything” was a Reagan-era, post-“Ferris Bueller” portrait that was just as monochromatic, but as others have pointed out, was more adult, kinder and gentler and just a bit more lived-in and real.

Like the rich, bullying brat Ferris, Cusack’s Lloyd Dobler is popular at school for no obvious reason. He’s not quite a loner, working class, not much of a dater. But he’s a kid who was out of the country for a bit and came back, a student slightly-older-than-average and thus a novelty.

I could never figure out why anybody would confuse Ferris Bueller with anyone you’d call “a righteous dude.” But Lloyd’s the guy everybody at a post-graduation pre-rave teen binge-drinking party surrenders their keys to. The party’s 20something host (Eric Stoltz) gives “key” duty to him because Lloyd’s responsible, compassionate. He’s not letting anybody drive home as drunk as his gonzo, blitzed jock classmate Mark (Jeremy Piven, of course).

Lloyd has few prospects in life but is utterly up front and blunt about what he sees his immediate future holding.

“What I really want to do with my life – what I want to do for a living – is I want to be with your daughter. I’m good at it.”

Maybe we don’t get the attraction, the “kick-boxing is the sport of the future” Lloyd pursuing and connecting with beautiful but insular and all-academics Diane (Ione Skye). But his posse of girlfriends, led by outspoken and intense Corey (Lili Taylor, just dazzling) and including Rebecca (Pamela Adlon, decades away from “Better Things”) do.

And Diane, noting Lloyd’s attentiveness, chivalry and genuine delight in introducing her to the classmates she spent four years not knowing, sees it too. She “gets it” at about the time the audience does, and long before Diane’s clingy, “stay focused” father (John Mahoney) hears that “I’m good at it” speech. Dad will never get it.

Think of all the high school parties depicted in rom-coms in the ’80s, and then watch Crowe raise the bar for all the teen comedies to follow. This party scene is brimming with life and fun, riotous but not out of control, engaging in all the subcultures it touches on. Everything before it imitated the gonzo “Animal House.” Everything after it was imitation Cameron Crowe. Richard Linklater’s “Dazed and Confused” would further codify how such fetes were filmed, after first being scripted and cast to perfection.

Cusack’s manic-patter in this picture was made for home video — “closed captioning.” He burns through the lines so fast that it’s no surprise that he grew up on Preston Sturges “screwball comedies,” where “faster, FASTER” was always funnier. Even when he’s heartbroken, even after he’s written a letter confessing his love and devotion and he’s sure he’s blown it, even when all he can do is leave a message on an answering machine he’s riffing run-on-sentences at top speed.

“Maybe I didn’t really know you maybe you were just a mirage maybe the world is full of food and sex and spectacle and we’re all just hurling towards an apocalypse, in which case it’s not your fault. I’ve been thinking about all these things and… you’re probably standing there monitoring. And one more thing – about the letter. Nuke it. Flame it. Destroy it. – It hurts me to know it’s out there. Later.”

Cusack was rarely this rat-a-tat-tat in his line-readings in the decades to follow, but we always knew it was there and it informed every character, every moment he let us see the wheels spinning, even if that spinning wasn’t spewing from his mouth.

Others were considered for Skye’s role as Diane, but the British-born “River’s Edge” actress brings a wholesome, smart but naive shading to this beauty-who-never-fit-in.

Crowe packed this Seattle production with Cusack cronies, most famously his unbilled sister Joan, who gives us working class reality in just a couple of scenes as his single-mom older sister. Lloyd’s emotional intelligence is on full display in how he plays the “fun uncle” to her little boy and still manages to understand her plight and her sensitivities.

Philip Baker Hall took another step on his road to no-nonsense immortality as the IRS agent who has to tell Diane just what her nursing-home-operator Dad was “guilty” of. Lois Chiles (also unbilled) plays Diane’s remarried mother, just a few years past her “Bond Babe” duties.

And then there’s the movie’s lone, loud false note. Bebe Neuwirth, already famous for “Cheers,” shows up at that post-graduation party as a too-sexy guidance counselor just “worried” about Lloyd, and anybody who ever went to high school can tick off the ways this is BS. She’s a wonderful actress, but that character should have never made the final cut. A little too “Bueller.”

The soundtrack, including that iconic Peter Gabriel moment on a boombox, was first-rate as you’d expect from the ex-“Rolling Stone” writer Crowe. And the milieu he set this in and the production design that realized it was as lived-in as you can get — from Lloyd’s beat-up late model Malibu to the crowded apartment he shares with his sister and her adoring, adorable moppet (Glen Harris).

But a lot of those elements “date” a movie. What makes “Say Anything” timeless isn’t the cast so much as it is the characters, and isn’t the story as much as the way it is told. The dialogue, crisp and (relatively) clean by modern, coarse and cliched standards, is its own “grand romantic gesture,” teen angst, teen curiosity and the teen dilemma incarnate.

We don’t know, at that age, what we’ll want for the rest of our lives. But we’re starting to get an idea of what we don’t want. And that’s what Crowe and Cusack & Co. hit right on the nailhead.

“I don’t want to sell anything, buy anything, or process anything as a career. I don’t want to sell anything bought or processed, or buy anything sold or processed, or process anything sold, bought, or processed, or repair anything sold, bought, or processed. You know, as a career, I don’t want to do that.”

Rating: PG-13, teen sex, teen drinking.

Cast: John Cusack, Ione Skye, John Mahoney, Joan Cusack, Lili Taylor, Eric Stoltz, Jeremy Piven, Pamela Adlon, Bebe Neuwirth, Lois Chiles and Philip Baker Hall.

Credits: Scripted and directed by Cameron Crowe. A 20th Century Fox release.

Running time: 1:40