A little of what you fancy does you good

"Giving the audience what it wants" has, for good reasons, become an accepted euphemism for substandard rubbish. So it's intriguing that Tuesday now offers two programmes that could be said to be doing exactly that - unashamedly indulging our communal desires - while at the same time being a distinct cut above the average.

The first, Due South (BBC1), is the most amiable of the two, a witty escapist fantasy from the US that pairs Constable Benton Fraser, a clean- shaven Canadian Mountie, with Detective Ray Vecchio, a Chicago cop who carries stubble enough for both of them. Fraser is an innocent abroad; he opens doors for old ladies, never cusses, leaves his gun in the office and blithely rents an apartment at the epicentre of Chicago's tornado of crime. He has moved out of his hotel because the windows are sealed shut and he is worried about getting fresh air. Vecchio wearily puts him right: "Fraser, this is Chicago. The only use for opening windows is to get a better aim."

"He's not some kind of nut is he?" asks the slum landlord to whom Fraser has politely offered his references. The short answer to which is "yes". Fraser is straight from the pinewoods and out of his tree, obedient to an inflexible moral code that allows for no accommodation to circumstance. When on ceremonial guard duty outside the Canadian consulate he is resolutely unblinking, however extreme the urgency of Vecchio's interrogations. The running gag emphasises the peculiar immobility of Paul Gross's performance - Fraser looks as if he has been injection-moulded, even turning his head with a doll-like stiffness - reminding you that the character is meant to be a daydream, a dummy who turns out to be smart.

The fantasy is one of moral assertion, of virtue's power over vice, and as such it makes a nice change from television's other fantasy of justice - that of men who cut corners to get the right result. After Dirty Harry, meet Spotless Fraser - a community policeman in a place where community is supposed to have imploded. For the dirty hero, human contact is something that results in well-deserved multiple fractures, for Fraser on the other hand it is a matter of being on first-name terms with the entire city (a particularly appealing fantasy for urban Americans - remember that yearning description of the Cheers bar as "a place where everybody knows your name"?) Instead of shooting criminals, he coerces them into submission by the insane charity of his expectations. The chase sequences are as tiresome as they are in every other US crime import, but the dialogue in between is something else altogether.

The second programme, The Politician's Wife (C4), meets a less benevolent desire: the general wish for some just deserts. Paula Milne's drama, about a betrayed Tory wife (no silly attempt to conceal party affiliations, I'm glad to say) is perfectly timed as an expression of electoral disgust but it is a pretty acute piece of human drama as well. Last night's opening episode was largely concerned with Flora's humiliation as the circus of ministerial adultery rolled into her life - the journalists laying siege outside and the damage-limitation team camped in the kitchen, trying to assess just what they can get away with. "Two months are all they've got," says one aide, scanning the tabloids, "Surely that's all he's got to admit to?"

The portrait of rat-like political cunning is enjoyable enough in itself, serving our appetite for some broadcast contempt, but there are sharp moments of truth too. "I was on a roll," Trevor Eve pleads, explaining his "momentary lapse" - a line which recognises that the aphrodisiac of power works on both parties, not just the pretty one. Alone in her room, Flora peels apart her nightdress to inspect her breasts, then covers them tenderly, a silent scene which was eloquent about the pain of betrayal.