When comedian, actor and author David Walliams was last on Ross's show earlier this year he was very funny; his incessant jibes nearly caused his Britain's Got Talent boss Simon Cowell to walk off set. But expect a more subdued Walliams here as he talks about his autobiography in which he admits that he has attempted suicide several times. I'm a Celebrity... winner turned TV presenter Stacey Solomon also guests and the music is by Ed Sheeran.

A welcome repeat of the enjoyable documentary, shown on BBC Four last year, exploring why sexual frustration still underpins British comedy. Leslie Phillips (star of the risqué Casanova '73) and Lesley Joseph (the insatiable Dorien Green from Birds of a Feather) are among the talking heads waxing lyrical on why Mildred didn't get it from George, why Terry didn't get it from June, and why the charmless Mr Rigsby spent his life wooing Miss Jones.

Narrated by former pin-up Madeline Smith (Phillips's fellow Casanova actress), the programme also examines the impact of the sexual revolution on British and, the more daring, American sitcoms. It suggests that the liberation of The Liver Birds was brought about by the abortion law reform and the introduction of the contraceptive pill, and that the shedding of inhibitions over the decades that followed resulted in the likes of the taboo-busting Gimme Gimme Gimme. But it seems that there's a lot of laughs to be had from being unlucky in love, and producers are sticking with the formula: the leads of The Young Ones, Men Behaving Badly, Ab Fab and the more recent The Inbetweeners got no more sex than their ancestors.

The penultimate episode of the amusing comedy drama about two teenagers who meet at a party and find out that 18 year-old Laura (Scarlett Alice Johnson) is pregnant. With three months until the birth, Laura is still living at Jamie's (Sean Michael Verey) house and his parents are keen for her to move back home. Meanwhile, Laura's parents Alan (Angus Deayton) and Janet decide to make a go of their marriage and plan a weekend break away.

Single Welsh mother Stella (Ruth Jones) is in high spirits as this fine comedy drama continues. It's son Luke's (Craig Gallivan) 25th birthday and so the family decide to throw a big party. But the birthday boy doesn't know what to do about the return of his estranged father. How will Stella react to the fact her ex is back in town? There's good news for fans, however: the show was recently recommissioned for a second 10-part run to air next year.

Mega-watt stars join the chat show host tonight. Actress Keira Knightley arrives to talk about her role as mental patient turned psychoanalyst Sabina Spielrein in her latest film, A Dangerous Method, which is based on Spielrein's turbulent relationships with Carl Jung and Sigmund Freud. David Beckham, who has a new line of underwear - being put out through high street chain H&M - to promote, joins her on the sofa. Scottish stand-up comedian Kevin Bridges completes the line-up.

Comedian Mickey Flanagan hosts a new series of the light-hearted stand-up show recorded at London's Hammersmith Apollo theatre. Tonight's guests are energetic rising star Seann Walsh, who muses on Tube-travel etiquette, and Irishman Jason Byrne, who performs a typically smutty routine about having sex with his wife.

If you're looking for a bit of escapism then you could do worse than visit the quaint Cornish seaside retreat of Port Wenn in this light - and hugely popular - family drama, now midway through its fifth series. It's easy to see why Martin Clunes's shirty surgeon decided to stay in the idyllic fishing port rather than return to life in London as he nearly did at the end of the last series. The sleepy pace gently washes over you and the magnificent views (in reality those of the village of Port Isaac, which is indeed in Cornwall) transport the viewer to a picture-postcard paradise.

Tonight Clunes's no-nonsense Auntie Ruth (the splendid Eileen Atkins) is on formidable form cheating at chess, berating her chickens, and wanting to "bring back capital punishment for people who use their mobile phones on the train". The programme avoids banality by touching upon some serious medical issues. When PC Penhale's (John Marquez) ex-wife Maggie (guest star Julie Graham) turns up thinking it is April 2008, the Doc quickly spots signs of transient global amnesia and arranges an urgent brain scan.

Pete (Hugh Dennis) and Sue (Claire Skinner) are left home alone when the Brockman children go their various ways for the weekend: Ben to an adventure camp where he takes pride in terrorising the teacher; Karen, who has written UGG on the side of her boots, to her fashion-mad friend Tanya's house; and Jake is out jamming with his bandmates. With all that spare time on their hands, the pair get a taste of what life will be like with an empty nest.

Sir Terry Wogan joins the panel this week for the comedy game show in which celebrities tell supposedly true tales for the consideration of a rival team. Wogan claims that he begins Christmas Day by firing a loaded pistol. Plus, comedian Kevin Bridges has to explain what happened when he found a suitcase of bananas. Team captain Lee Mack is also joined by his Not Going Out co-star Katy Wix, and David Mitchell welcomes his comedy partner Robert Webb].

The film in which Leslie Phillips first uttered his immortal catchphrase: "I say, Ding Dong!" Hattie Jacques is the no-nonsense matron presiding over accident-prone trainee nurse Joan Simms, who decides to get even with an overbearing Colonel by sticking a daffodil up his you know where.