Alyson Hannigan

’’How I Met Your Mother" has become this season’s almost-great sitcom. And by ’’almost," I mean ’’definitely on its way there" as opposed to ’’never will arrive." Despite the fact that it’s a traditional laugh-track comedy, despite the fact that it’s trapped in CBS’s old-school Monday sitcom block, and despite the fact that it’s stubbornly and sincerely romantic, ’’How I Met Your Mother" is a TV winner in the making.

Why ’’almost"?

I hate to nitpick, but — OK, busted, I love to nitpick — the show has a few kinks to work out before it gets a solid A. But the good news is that the obstacles to excellence are small and easily addressed. By the way, by ’’excellence" I don’t mean it will compare to ’’Curb Your Enthusiasm" or any of the boldly original series that have been redefining TV comedy. I mean that it will be the next ’’Friends" — that is, the next four-camera charmer that’s unashamedly mainstream, that’s set in New York, and whose characters never seem to be at work. The ’’Mother" gang of five — neurotic Ted, commitment-phobic Robin, Barney the viper, and engaged couple Lily and Marshall — form an ensemble that, as on ’’Friends," is warm and lived-in no matter how punch-line driven it is.

The most buzzed-about element of the show, which airs Mondays at 8:30 p.m. on Channel 4, is Neil Patrick Harris, who has shape-shifted from a goody-goody character into a symbol of all things slickly unromantic. His Barney is a classic last-call bar hawk, representing every urban professional male who is metrosexual enough to wear fine suits but still views women as objects. The show’s writers clearly love filling Barney’s mouth with Seinfeldian catch phrases that reveal just how Barney Barney truly is. His ’’Suit up!" has evolved into ’’Snow-suit up!," ’’Flight-suit up!," and ’’Penguin-suit up!," and when he tries to seduce others into stupid activities, he promises it will be ’’legendary." He also likes to do ’’phone-fives," which are high-fives via cellphone.

The list of Barneyisms goes on, but the writers need to remember that he is a character, too, and not just a jukebox of quips. Right now, he serves as the perfect anti-Ted, the one whose sharp lines deflate Ted’s dreamy fantasies about true love. ’’You don’t bring a date to a wedding," he scolds his friend. ’’That’s like taking a deer carcass on a hunting trip." But as time goes on, Barney’s human limitations could easily wear thin. I hope the writers can add more dimension to him without betraying his delusions of grandeur.

It’s not easy to expand a one-joke character late in the game, as the ’’Friends" writers discovered when their efforts to evolve Joey were maudlin and unbelievable. ’’Will & Grace" has also struggled and failed to give Jack heart and depth.

Lily turns out to be another potential problem character. Alyson Hannigan was so affably fickle and hypnotic as Willow on ’’Buffy the Vampire Slayer," but she seems less comfortable with the fast sitcom pace. She appears to be gasping for air inside her lines, and her sweetness borders on dullness.

Cobie Smulders is a revelation as the robust Robin, as she bends gender to suit her big personality. She calls everyone ’’Dude" and recoils from the lovey-dovey, and yet she’s all about the va-va-voom in her glamorous red dress. But Hannigan’s Lily is a wan girlfriend in danger of becoming just one more TV gender cliché, a woman bent on taming her man and getting him to shop with her. While all the other characters have been given last names, Lily hasn’t, as if she exists solely to be Marshall’s fiancée. She needs a life.

A number of viewers have said that Josh Radnor’s Ted is the flaw in ’’How I Met Your Mother." Ted is the show’s hero, the narrator who’s telling his future son and daughter about his life as a single guy, and Radnor makes him into a lovable but hyper mensch. I think Radnor is a welcome softie in a genre that’s often driven by horndog dudes who proudly ignore emotional realities. He’s the Charlie Brown and the Linus, the guy who has a lot to learn as he tries to assert himself to find ’’the one." He’s the human center of the show, and it’s his life that forms the compelling mystery — who will become the mother of his children?

We can only pray the writers don’t get all Ross and Rachel on us with Ted and Robin, pushing them back and forth until we don’t care if they wind up together. The great surprise in the series premiere was that despite Ted’s crush, Robin was not ’’your mother," but ’’Aunt Robin." And since then, Ted has embarked on an equally convincing crush on Victoria (’’Buttercup"), played by Ashley Williams. If Ted and Victoria don’t work out, let’s hope we’re not facing years of on-again off-again culminating in — snore — ’’Did she get off the plane?"

’’How I Met Your Mother" also has a few stylistic glitches. Calling it a conventional sitcom is not completely accurate. Most of it is, but then it employs some contemporary tricks, including freeze frames and split screens. The two approaches sometimes clash, for instance when we hear audience laughter during one of Ted’s voice-overs. Also, the New York stages aren’t entirely convincing. They’re too bright, not gritty enough. They slightly undermine the urban atmosphere.

’’How I Met Your Mother" does well what so many sitcoms do sloppily. The characters pick on one another, but the teasing is a sign of affection. The show isn’t all about a superficial world of every man for himself; it’s about the consolations and lessons of friendship. And that’s why I feel the need to pick on ’’How I Met Your Mother." It’s too likable to ignore.