Sheer affection for the hapless Brockman clan sustains this seasonal episode, which, although perfectly watchable, isn't up to the standard of their last Christmas special. We may even be coming to the end of the line for this excellent series - the children are getting older and seeming more like regular middle-class sitcom kids, rather than the striking, precocious infant improvisers of yore. Tonight, a Premium Bond win has afforded them the opportunity of a Christmas break in the sun. But before the airport dash, there's an emergency trip to the dentist for Karen and a visit to a now ward-bound granddad, lost in a world of sing-song.

This strange and generally wonderful series takes a slight misstep in the final episode of its run, in the form of Dan's girlfriend Anita, a thoroughly obnoxious (but more scripted than fully realised) character. Still, the torments to which she subjects Steve and Becky's neighbour make for some very funny and moving scenes. Dan's small talk with Shelly - "How have you been?" "You know." "Yeah." - sighs volumes of enduring melancholy. As for the couple themselves, their stoical cheer and happiness in each other's company, despite frequent outsider intrusions on their lovenest, is put to the test by a calculatedly offhand remark by Steve's ex.

If you think this series has been iffy so far, you're advised to tune in tonight, if only to have your worst fears confirmed. As Warwick copes with divorce negotiations with only his accountant for representation and checks out a new flat with his idiot PA, we're subjected to a relentless volley of little-person gags that leave us, like the estate agent, looking on with unsmiling, dumbfounded horror. How on earth was this ever waved through? What happened to Gervais? As ever, redemption comes briefly in the form of the celebrity insert - this week, it's Steve Carell.

The opening few minutes of this excellent sitcom say as much about the male of the species home alone as Simon's Cat does about cats. It's not long before family and neighbours intrude, however, to gather optimistically around the television for the lottery. Laura is an eloquent study in bigotry and she's convinced Paul has a cancerous lump on his testicles. Meanwhile, Dan drops in with his seemingly nice cousin Alex. Steve and Becky are, as ever, superb, so comfortable in the proximity of each other's skins.

Ricky Gervais and Stephen Merchant only appear briefly, but their stamp is all over this sitcom, with Warwick Davis as the showbiz dwarf who is essentially Gervais by proxy, and his worse than useless female assistant in the Merchant role. The humour is progressive - where else would Davis get a leading role like this? - yet too constantly fixated on height for jokes. Tonight, Davis wangles work both as a consultant to Johnny Depp and a guest gig at a wedding, but the centrepiece of this episode is embittered, fragile Depp's showdown with Gervais in his office, vengeance for the roasting he got at the Golden Globes.

This series is gaining admirable steam, and tonight's episode begins with a virtuoso exchange of self-pity between Jerwayne and Ashley. The latter finds his milkshakes rebuffed by a pair of scornful young girls, his bald patch enlarging and the need to "identify new territories" - the older woman. She arrives in the form of the replacement training lady and the pair compete with Lance to charm her. Janine, meanwhile, is convinced she has a stalker, a fate she meets with alarming equanimity, as well as empathy. She knows what it's like - "I put the hours in. Just ask Gary Barlow's mum."

With a rhythm, a feel and a character all its own, this bleak gem of a sitcom is possibly BBC3's sole redeeming feature. Tonight, Steve and Becky throw a dinner party to mark their cohabitation, while their ghastly array of family and neighbours get to do their worst. A feeble anecdote about an 82p banana triggers off some alarming conversational tangents, not least Laura's intention to join the BNP. Mike, Steve's mum's new boyfriend who takes full advantage of the open door toilet policy, turns out to be relatively un-appalling.

Back for a second series, the mobile-flogging crew are feeling the effects of the economic downturn, with their mantra - to "shift units, make money, smash targets" - increasingly difficult to realise. In this opener, Ashley, Jerwayne and Christopher angle for ways to make money on the side, while Janine finds herself mixing with Croydon's own creme de la creme. Some consider PhoneShop to be a funny but grotesque exaggeration of south London mores, with its Office/Ali G shtick. Those who have lived in the Croydon/Sutton area, however, assure us that this is a scrupulously naturalistic depiction.

With its rather awkward device of a sports anchorman and ex-footballer providing a running commentary on the life of sports journo and man-child Pete Griffiths (Rafe Spall), eyebrows were raised by some when this was commissioned for a second series. However, while it could still do without the sidebars and graphics that pop up, this is actually funny, and much of that is due to Spall. Here, he has to eke out a supplementary living as a dog walker, with fatal consequences, while romance possibly beckons with his parents' new Polish home help, the "good Catholic girl" Gracja.

It's been with us some 15 years now, and, in the wake of Have I Got News For You, has reached that stage of its maturity where it has guest hosts. This week it's David Hasselhoff, whose career of affectionately parodying his Hasselhoff persona has outlasted his earlier, un-ironic one. Regular team captains Phill Jupitus and Noel Fielding are on hand, joined by Pineapple Dance Studios star Louie Spence, Amelle Berrabah of Sugababes and the ever-reliable Peter Serafinowicz.