No one on television can match Jilly Goolden for enthusiasm; there have been whole wars that were less noisy. With her blonde curls and light colouring she calls to mind an exuberant, licky dog - a giant albino poodle, perhaps, whose Pal has been spiked with Ecstasy. "Gosh!" she barks excitedly, "wow, wow!"

Having graduated from Food and Drink, Jilly is now wagging her tail in front of millions on The Great Antiques Hunt (BBC1, Sunday). This week - together with a cast of fops and Roy Strong impressionists, arrayed in the antiques expert's uniform of bow ties, knickerbockers and purple shirts - she was accompanying two teams of Americans, to experience Oxford's "dree-aming spires". Giant poodles are rarely intellectuals and once having got hold of a good phrase they are reluctant to let it go. Thus every time Jilly mentioned "Oxford", these words - "dree-aming spires" - appeared close by.

The show itself is a diverting CD-ROM guide to things old and beautiful, in which the teams play five games to do with the world of antiques. On one side last week we had two fat American bachelors, outfitted in a ghastly green - like a parody of Robin Hood, starring hippos. Facing them was a skinny, red-suited brace of Yank power-women, one of whom lived with her "two adorable children", and the other who boasted of her "beautiful house and dawg".

The teams had 20 minutes to buy an antique in a Massachusetts market, took part in a "guess the price" competition in an antiques emporium situated in the heart of Oxford's "dree-aming spires", acted as tour guides in Blenheim palace, dated buildings amongst the (all together now) "dree- aming spires" of Oxford, and - finally - took turns as auctioneers. After a lot of chat about Dooks and Toodurs the green hippos won, and were allowed to pick some cheap plates as a prize (in preference to the truly valuable ugly useless wooden thing which - had they been true experts - they would have chosen). "Gosh," barked Jilly, and widdled all over a William IV pouffe.

Connoisseurs could contrast this breathless gallop through antiquery with the evenly paced authored pieces in The Antiques Show (BBC2, Monday). If Jilly has stepped from the pages of the Famous Five, the elegant and cool Francine Stock (who looked every bit as good as some of the finest pieces on display) inhabits Le Grand Meaulnes. It is hard to believe that they share the same DNA structure.

But this is a matter of scheduling and branding. BBC1 is more personality- based and in yer face; BBC2's leisure shows are gentler, slower affairs, full of long, loving shots, stippled water and the plash of whatever it is goes plash. And in Tales from The River Bank (BBC2, Monday) it was fish that plashed.

Wonderfully introduced by Geoffrey Palmer, this series aims to answer the question most people ask about fishing: why? What is the obscure magic that draws chaps to muddy riverbanks, there to chase the flashing scales - usually in vain? Is it the natural beauty, the loneliness - or is it just the same inadequacy that transforms sensible family men into football fans and stamp collectors, and women into grass widows? When one young fellow spoke of the pleasure of fishing for "big barbel on a misty dawn", I understood him. I once met a German girl called Barbel.

However, I had no desire to understand the chap - his wide face and simpleton's mouth reminding me of Benny Hill - whose attire consisted of a silly hat festooned with coloured flies, a multi-zipped flak jacket and waders up to his armpits. Threaded through a lorry's inner tube, his flippered feet appearing at one end, he floated along an otherwise beautiful river - a pneumatic eyesore - trying to take fish by surprise. The ruse worked, said Benny, "because they probably don't realise what I am". Which is what, exactly?

If fish plashing is not for you, perhaps you'd like to go hill-walking in North Wales this summer. If so, don't expect to find solitude. As the first in Visions of Snowdonia (BBC2, Friday) made clear, there are too many folk in them thar hills. With warden Sam Roberts (a Welsh speaking hedge poet) we watched as silly Brummies wearing trainers slid from the ridges of Crib Goch, or eroded the Pyg Track.

This was a pleasant, low-key and undemonstrative film that gently raised questions about sustainable tourism, such as why do we allow folk to hold races on our best mountains, leaving a horrid residue of exertion-related litter behind them? C'mon Chris Smith or John Prescott - ban it!

Unfortunately I had no time myself to ponder Ming vases while casting my line for chubb in the shadow of Cader Idris. This was because I spent most of the week watching Melissa (Channel 4, Monday-Wednesday). And a bloody good time I had too, though the dynamic and brilliant world of TV criticism has been divided by this series. The reason for this is that - with the blessed Potter dead - Alan Bleasdale (who wrote the series) is now the last Great Televisual Artist, which is a substantial cross to bear. Some of my fellows believe that Bleasdale, by adding to a Sixties thriller penned by an unspeakable bourgeois called Francis Durbridge, has let himself down.

I think quite a lot of them are dismayed by the fact that the world depicted in Melissa is familiar to them, unlike the world portrayed in Boys from The Blackstuff and GBH. They see journalism traduced, critics caricatured, the novelists shown as drug-crazed and sex-mad. "It is not real!" they cry. GBH , of course, wasn't "real" either, but they didn't know that. We who live in Kentish Town, on the other hand, commune daily with the real world, and we know.

So, having a go at Bleasdale's verisimilitudes is like criticising Murder On The Orient Express for its lack of probability ("You what? They all did it? Come on!"), or Evelyn Waugh for his exaggerations of the Thirties beau monde. Melissa did not start with a caption saying, "the events in this film are based on a true story". As this brief reprise (for those of you who have missed it) indicates: damaged journalist Guy (car crash, dead girlfriend) falls in love with damaged PR woman Melissa (dead parents, dead baby), sucks the nail varnish from her fingers, and agrees to marriage while still sticky from their first shag. "Why not?" he asks. Because she's bonkers, Guy.

She in turn introduces him to her rootless set of PR and agent chums (Agatha Christie meets Absolutely Fabulous), who get together in a perpetual drinks party. Around them, however, people are dying, and we do not know why. Visits are made to safety deposit boxes, psychiatrists harbour ancient secrets, guns arrive in the post. And then Melissa herself gets it, and Guy is discovered bending over the bloodied corpse.

Much of this is just splendid. The seedy menagerie surrounding the voluptuous Melissa (played with giggling menace by Jennifer Ehle) are horribly reminiscent of the hedonistic, alcoholic, unhappy goodtime world of Ruth Ellis and her racing-driver boyfriend, (remember Dance With A Stranger?) And indeed there is an emotionally crippled blonde hostess - Hope - who has the hots for an apathetic racing driver.

The writing itself is an eclectic mix of early TV whodunnitry: "We know a lot about each other, Melissa." "Too much!"; and - on the other hand - modern wit. Playing one of a pair of cultured policemen, that Bleasdalian stalwart, Michael Angelis, looks up at an enormous muscly gay man and asks him whether he practised safe sex. Not always, the giant replies. "Well you should have!" shouts Angelis, pressing his face belligerently into the man's diaphragm.

I am cross about only one thing: the uselessness of the reprise at the beginning of each episode. This is so cryptic that it more or less tells any viewer who has had the temerity to miss the previous instalment, to sod off for being so dilatory. Not nice.

Nevertheless everybody I have spoken to about it wants to know what happens next and has a theory about the murderer/s. Hope did it, Guy did it, Paula did it. Such involvement is the real test of a thriller; so while Melissa may not be Great Televisual Art, it is a good reason none the less for owning a TV set.

Just occasionally the death on screen is real. So the highlight of the week was Tuesdays' Newsnight, in which Jeremy Paxman's 13 repetitions of the same unanswered question - "did you threaten to overrule him?" - probably killed off whatever remained of Michael Howard's tacky political career. Soon he too will be free to date Oxford buildings, to sit in an inner tube, or (contemplating the blood on his suit) to wonder whodunnit.