The Good Wife: the best US drama you've probably never watched

Maybe it's the unpromising premise, the trailers that make it look like a tawdry love in the workplace melodrama or the title that makes it sounds like a made-for-TV clinker – but in UK discussions about quality TV, The Good Wife is often overlooked. It's a massive oversight: over its first two seasons the show has established itself as the best legal drama in years; consistently smart and inventive, with terrific performances throughout. The third season kicks off on More 4 tonight – and if you haven't tried it before, now is a good time to begin.

Michelle King, who created the show with her husband Robert, stumbled upon the idea while observing a succession of political scandals that featured contrite male politicians alongside silently stoic wives. "We asked, 'What are they thinking?' And Robert and I started talking about it from there," King said in an interview about the show. "You know, what's interesting about a lot of these political scandals is that the women are lawyers, too. Hillary [Clinton] is a lawyer. Elizabeth Edwards is a lawyer." Thus was born Alicia Florrick (Julianna Margulies), mother of two who returns to work as a lawyer after her state's attorney husband Peter Florrick (Chris Noth), is jailed after a prostitution and corruption scandal.

Margulies is particularly good at portraying the central conflict in Alicia – the clash between the antipathy she feels towards her husband and her desire to keep the family together. Nursing private wounds from a very public humiliation, she has to get back on a horse she dismounted 13 years previously and returns to work as a first-year associate at Stern, Lockhart & Gardner, a position she gets through an old friendship with senior partner Will Gardner. The obvious chemistry between Alicia and Will fuels a will-they-won't-they relationship that gives a certain frisson during the understandably frosty post-scandal relations with her husband.

But it's the supporting cast that really make The Good Wife – and chief among them is British actress Archie Panjabi who won an Emmy for her powerhouse performance as Kalinda Sharma, the firm's in-house private investigator. Although smart as a whip and dogged as they come, Kalinda will happily use her sexuality to get what she wants. After Ellen called her "the best bisexual character on TV" although we have only gradually learned about her orientation and the mystery of what motivates her is part of her appeal. The only thing we can say about her with any certainty is that she's brilliant at her job and she'd be happy knowing we were largely in the dark.

Also impressive is Michael J Fox who plays intriguing recurring character Louis Canning, a brilliant Machiavellian lawyer whose tussles with Alicia are memorably vindictive. Fox clearly has a blast playing the role and it's telling that Canning's disability (a necessary character point because of Fox's Parkinson's) is referenced but never obsessed over.

Given the restrictions of network programming where formula is king and morality campaigners lobby your advertisers if you so much as a hint at an arse cheek, The Good Wife does a fantastic job in producing an engaging grown-up legal drama. For me it's up there with Community and Parks and Recreation as one of the best network shows currently broadcasting.

Perhaps more importantly, its vulnerable yet strong protagonist claws back some of the ground lost by Ally McBeal in the credible depiction of female lawyers. And for Julianna Margulies, years of mooning after George Clooney on ER are forgotten – she's compelling and three-dimensional here, just like the show she leads.