Much of the answer lies in the lively and impassioned performance of Jack Nicholson as Melvin Udall. Thanks to a rude personality and an advanced case of Obsessive Compulsive Disorder, Melvin is prodigious at making the lives of others and himself miserable. He spews out hateful, bigoted remarks at anyone who comes his way. He's so vitriolic, he even upsets fellow New Yorkers. His eccentricities make him even more repulsive. He avoids cracks in the sidewalk (making himself look like a wounded spider) and insists on bringing his own utensils to restaurants even if it offends the staff. One might wonder how someone like Melvin could hold a job, but that's not problem because he makes a healthy living as a romance novelist.

When his artist neighbor (played with surprising skill and empathy by Greg Kinnear) is robbed and severely beaten, Melvin reluctantly takes care of his dog. Pretty soon he and the pooch become friends, and the emotionally stunted Melvin actually cries when they have to part ways. In addition, Melvin starts helping a waitress (Helen Hunt) take care of her asthmatic son.

Director James L. Brooks (Terms of Endearment) knows how to tug at your heartstrings without insulting your intelligence. As Good as It Gets is sweet, but contagiously so. Brooks' off-handed and loose storytelling gives the movie a sense of needed spontaneity, and the warmth of Kinnear's and Hunt's performances are an ideal counterpoint to Nicholson's bile.

For his part, Nicholson, who sometimes coasts on his bad boy persona, actually develops a full-bodied character this time. In addition to the ticks associated with his character's OCD, Nicholson demonstrates a much wider range and more sensitivity than he has in some of his more recent roles. His natural charisma also comes in handy. In the early portions of the film, Melvin stuffs little dogs down garbage chutes. In the hands of lesser actor, Melvin might have been unbearable. Brooks knows Nicholson's in rare form. While he and co-screenwriter Mark Andrus have penned a lot of snappy wordplay, Brooks' camera spends more time on Nicholson's face than his mouth. It's a riot watching Nicholson squirm whenever anyone else expresses gratitude to him.

Yes, this movie has an enormous soft spot. But thanks to some solid laughs, Brooks' honest approach and Nicholson's masterful performance, As Good as It Gets proves that sentiment isn't such a bad thing ( R ). Rating: 9.