The school-based sitcom playground is getting pretty crowded, with the bell just rung on Big School and Jack Whitehall's Bad Education still running around dropping its shorts at anyone who's interested. But for my money the pick of the Class of 2013 is Some Girls (BBC3), which scores one vital A* over the opposition: it looks as though it's set in a school that might actually exist.

On the face of it, the group of south London bffs at the heart of Some Girls is painfully PC: one sorted black girl, one ditzy white blonde, one brainy Asian and one baby Kathy Burke. So it's full credit to the spark in the writing of Bernadette Davies and a set of confident performances from the four leads that this formula adds up to more than the sum of its parts. It works.

Led from the front by Adelayo Adedayo as Viva, who was facing down the tricky issue of dumping a fit boyfriend who was too thick for her, last night's episode centred on the sudden death of a science teacher - cue the arrival of Broadchurch's Jonathan Bailey as unashamed lust object - and the fallout therein.

It was all dealt with delightfully distastefully, as voiced by the straight-talking Aussie gym teacher/resident hard-faced bitch: 'We'll provide a counsellor - if you can't talk it over with your mates like a normal person.'

The first series of sixth-form girlcom Some Girls was savaged by some on the basis that it wasn't The Inbetweeners. And fair enough: while the characters were as vacuous and clichéd as their E4 male counterparts, they were seldom as funny. But the opener to this second run suggests a mild reappraisal might be in order. The characterisation has scarcely moved on, but the performances are more confident and Bernadette Davis's writing rings a little truer.

We rejoin the girls shortly after sensible Viva (Adelayo Adedayo, the best thing in it) finds a dead teacher in a store cupboard. Enter an eminently fanciable counsellor (Jonathan Bailey), rapidly courted by bimbo Amber and aggressively on-heat Holli. It's no masterpiece, but its eagerness to please lends it a certain surreptitious charm.

Me and Mrs Jones opens with a goldfish in a toilet bowl. I can only guess that the goldfish took one look at the script and attempted to escape before his television career suffered irreparable damage.

Of the many unkind epithets suggested by Roget's Thesaurus, 'excruciating' is the one that best describes this show. Until I watched it, I did not realise it was physically possible to grit one's teeth, curl one's toes and clench one's sphincter all at the same time. And stay that way for half an hour.

Purportedly a romantic comedy, it is about as light and fluffy as a breeze block. Not the most sparkling of analogies, I grant you, but better than anything the lazy and witless script of Me and Mrs Jones had to offer.

"Houdini would have trouble getting out of this dress," grumbles our scatty, sexy heroine Gemma, as she writhes around in a store changing room. Houdini? The escapologist who died 88 years ago? Watch out for further thrillingly contemporary references to the general strike, Irish home rule, speakeasies and the disappearance of Amy Johnson.

Where the show strives to charm, it succeeds in irritating. I am a fan of Sarah Alexander, who plays Gemma, but here I found her wackiness so mannered as to be unbearable.

But the worst thing about Me and Mrs Jones is that no part of it rings true - not the characters, not the relationships and definitely not the dialogue. Romantic comedy needs to appear effortless, but every minute of this contrived, constipated monstrosity screams with the strain of it all.

A solidly dependable cast, including Nathaniel Parker and sitcom stalwart Neil Morrissey, tries so desperately hard to unearth humour from the barren comic landscape that I actually began to pity them. This is particularly true of Jonathan Bailey, lumbered with the Herculean and ultimately futile task of lending sympathy to Alfie, Mrs Jones' unremittingly loathsome eldest son, just back from his gap year abroad. Apart from a big mouth, an overinflated ego and a penchant for harassing women on public transport, Alfie also has a best mate in tow, who just might hit it off with his mum over the next five episodes.

Off the Hook follows a group of freshers as they embark upon a new life at university. Stock student behaviour such as partying, slovenliness, unrequited love and stealing your flatmate's provisions are all present and correct, the last of which providing a neat and unexpected plot twist when the purloined pint of milk turned out to contain a bacteria sample.

Jonathan Bailey as Danny has the thankless task of playing straight man to the various inadequates, slackers, party monsters and misfits he shares digs with, but he pulls it off with considerable charm. Danny Morgan as his brash, insensitive mate Shane is a little too reminiscent of Smithy from Gavin and Stacey for my liking, but was horribly watchable nonetheless.

If the protagonists and set ups aren't wildly original, Off the Hook does capture that curious combination of innocence, invincibility and imbecility typical of many 18-year-olds away from home for the first time.

Having debuted, as Fresh, on the BBC's Switch website last year, this surprisingly funny youth-oriented sitcom about a group of university freshers makes its transition from internet to terrestrial television this afternoon (it's also being shown on BBC Three on Thursday evenings). Episode one introduces us to Danny (Jonathan Bailey), a new student full to the brim with the promise of romantic, social and academic success - and about to be sent reeling by the arrival, via clearing, of his freeloading best friend Shane (Danny Morgan).