By Jay Carr, Globe Staff, 12/23/97

``As Good as It Gets'' reminds us that most film comedies today aren't as funny as the best TV sitcoms. ``As Good as It Gets'' is as funny as the best TV sitcoms, and that's what sets it apart from most Hollywood studio comedies. With Jack Nicholson as a misanthropic romance novelist with obsessive-compulsive disorder, Helen Hunt as a forbearing sweetheart of a waitress who puts up with him daily because he's a minor irritant compared to her other problems, and Greg Kinnear as a painter who lives next door and still hasn't worked out some issues connected to his homosexuality, ``As Good as It Gets'' is the final nail in the coffin of the lazy and now obsolete critical habit of insulting a film by likening it to a sitcom.

This new James L. Brooks film plays like sitcom on a huge budget -- so huge and, at two hours-plus, so lengthy that it sometimes seems bloated. Yet it reminds us that things like coherence and seamlessness can become unimportant when the screen is filled with entertaining characters. And characters, of course, are what drive sitcoms. Led by Nicholson, these three always find ways around the obstacles placed in their path by structural clumsiness. What it's also got that TV hasn't got is Nicholson, reminding us with rigid body language and little involuntary frowns, how involving and deliciously entertaining he can be even when he's working with about a third of what he's got at his disposal.

Restraint and control, not going full throttle, are what make Nicholson's character so improbably engaging. As a rich, bigoted, homophobic curmudgeon, he's funny when he first extends his fussy, rejecting manner to his neighbor's yippy little dust mop of a dog, tossing it down an incinerator chute in his Greenwich Village apartment house. He only leaves his apartment for his daily brunch, carrying plastic utensils to the neighborhood restaurant he blights each day, carefully stepping over every sidewalk crack on the way, secretly feeling relief at the familiar and tolerant waitress played by Hunt, who is impervious to his grouchiness.

He makes us feel he sees the daily ritual as a trip through a dangerous minefield, makes it seem pathetic and hilarious. His tight little closed circuit becomes undone when the neighbor is beaten up and he's pressured into caring for the dog that has emerged from the incinerator feistier than ever. This is where the film gets tricky. The reason Nicholson's novelist is so defensive is that he's got a lot to defend. But Nicholson, ratcheting down the guy's iron curtain one gear tooth at a time, makes palatable the fact that his grinch is a pushover. He not only falls for the dog, but arranges medical care for the waitress's asthmatic young son because, he says, he hates deviations in his routine and doesn't like the idea of being inconvenienced when she stays home to care for her son.

She, meanwhile, hates the idea of being obligated. But hardly have they begun to grapple with this complication than they find themselves shepherding the painter by car down to Baltimore, where his parents live, and where he must go to retrench. What happens is predictable, and the way it happens hardly represents smooth joinery. But the film's all-over-the-place quality and tonal flip-flops are more than hurdled by the charm of the leads, by the slow, hesitant edging together of the novelist and the waitress, even though each feels more comfortable in the safety of the unattached state to which each has grown accustomed.

Nicholson has done some of his juiciest work with Brooks and he's doing it again here, in a slightly diferent way. The key to their successful collaborations is Brooks's embrace of idiosyncrasy. Here it allows Nicholson to flash his eyes, but with fear, not with the devilish confidence he has so often flashed before. He never forgets that the crusty author he's playing is soft beneath his shell. He's a man in hiding, emotionally. What draws him to Hunt's waitress is her decency and honesty. Which can make problems when she rightly says to him, after an approach he intended as romantic, that he keeps ruining things by being himself.

It's Hunt's breakthrough role, proving conclusively that she can make the jump from the small screen to the large one. She's the best working single mom Hollywood has put on screen since Renee Zellweger in ``Jerry Maguire,'' and she's altogether endearing. As the catalyst, Kinnear gets back on the fast track he rode in ``Sabrina'' after falling off it in his last few films. In a role that's predictable, he somehow finds ways to avoid seeming obvious, while exerting his own quota of charm. I'd go to ``As Good as It Gets'' and not worry too much about its structural ungainliness. Nicholson, Hunt, and Kinnear will win you over as they turn the film into a valentine to New York's walking wounded.