Mary-Louise Parker is morally compromised, hypocritical and -- oh, yeah -- a criminal in Showtime's new half-hour comedy, "Weeds," which premieres tonight at 10.

And she's fabulous at all of it.

Those bemoaning the death of the sitcom would be wise to get pay cable, because Showtime's subversive new offering is smart, funny, human and truly likable -- all adjectives that could also describe its star, despite the major flaws built into her character.

Parker plays Nancy Botwin, a mother of two living in fictional Agrestic, Calif. Her husband has recently dropped dead in his prime, leaving her with a big house in the suburbs, a leased Range Rover, the two kids and, clearly, not enough life insurance.

Her solution? She starts dealing pot. She deals at her son's soccer games. She deals at the local poker night. She deals to her accountant. She deals, in other words, to the kind of people who live in her neighborhood.

And what kind of neighborhood is that? Well, as Malvina Reynolds's "Little Boxes" plays during the opening credits ("And they're all made out of ticky-tacky, and they all look just the same"), the visuals are of upscale cookie-cutter houses where every car is a Range Rover, every dad is buying his $4 morning latte and every mom is out in identical workout wear, taking the morning jog. It's a neighborhood of PTA moms who cattily discuss how Nancy can still afford her big designer bag on what her husband left her (it's a knockoff), while their kids are all out drinking and having sex by age 15.

Parker has been a scene-stealer in much of her work -- her turn as Amy Gardner on "The West Wing" is a prime example -- but this time it's her show, and she makes the most of it. Why deal drugs? Because, she admits, she doesn't want to "end up the oldest Gap salesperson in California." Sure, she needs money -- the phone gets turned off, she bounces a check on her son's karate teacher -- but it's quite evident that she's dealing not out of true desperation but rather because of the desire to maintain her previous lifestyle. Downscale the household? No way. Fire the housekeeper? But she's family!

Sound wholly unlikable? Ah, but that's the beauty of Parker's talents. She's a moral mess and a decent mom and sympathetic character all at once.

She strong-arms a teenage dealer into no longer selling to kids -- when she hears a 10-year-old was caught with marijuana, she's truly horrified -- but continues to deal to the parents. She spearheads the battle to get soda machines removed from her kids' school, all the while cooking up pot-laced popcorn balls in her newly renovated, granite-counter designer kitchen.

And then there's the fallout from her husband's death to contend with. Her older son, Silas, is 15 and fixated on girls and sex, and she's at a loss as to how to advise him. And younger son Shane is dealing with the death of his dad by alternately losing himself in videotape of his lost father and engaging in self-destructive behavior that routinely gets him hauled in to see the counselor at school.

Created and executive-produced by Jenji Kohan (a former writer for "Tracey Takes On . . .," among other shows), the show is very well cast. Kevin Nealon co-stars as Nancy's accountant with a habit, and Elizabeth Perkins plays Celia, a fellow mom whose own moral bankruptcy (albeit not of the illegal variety) deftly plays off Parker's. Perkins is wonderful as a bored and disillusioned housewife who shows little to no sign of loving her children. She is horrible to her overweight younger daughter, whom she refers to as "Isabelly" and secretly feeds chocolate laxatives. She despises her husband (give her this, though: He is cheating on her with a tennis pro). As for her older daughter, at one point she admits out loud that she wishes she'd had an abortion. There's a soul in there somewhere, though; it just may take a few episodes to find it.

Kohan flirts with some dangerous dialogue -- including references to Anne Frank, "The Passion of the Christ" and the sexual appeal of the handicapped -- that will surely raise some eyebrows. This is a show that had to be made for premium cable, and takes advantage of its home to include some blatant, and sometimes vulgar, references to sex, but they rarely seem gratuitous.

One cringe-worthy moment comes early in the first episode, when viewers are introduced to the African American family that provides Nancy with her pot supply. Stereotypes abound, and it's tempting to write off that aspect of the show as a bad -- even offensive -- cliche. But buried under the racially charged jokes is the relationship Nancy forms with the family. The son, Conrad, in particular, can't help but be concerned for her -- they may all joke about the foolish "white girl," but they are well aware that she's in way over her head. Over her head, and still living in her little ticky-tacky world, where denial is so comfortably at home.

Weeds (30 minutes) debuts tonight at 10, then airs Mondays, Wednesdays and Fridays at 10 p.m. on Showtime.

Mary-Louise Parker becomes a dope dealer to maintain her family's affluent lifestyle in "Weeds." Tonye Patano (seated) and Romany Malco are also featured.Elizabeth Perkins plays a bored housewife with a mean streak. Kevin Nealon is cast as an accountant with a bad habit.Mary-Louise Parker brings an essential likability to the lead role in Showtime's subversive, and risky, new comedy.