Comedy/Edinburgh: Mine's a mineral water

If you notice a Perrier theme to this week's column and a new note of manly authority in my reviewing, it's because, after years of making cynical comments about the Perrier award, I've put the "critic" into "hypocritical". I'm one of this year's judges. So far, it hasn't been a very arduous office - the worst part has been all the phone calls from colleagues asking, "What's all this about Al Murray, then?" Murray, in character as the Pub Landlord, was shortlisted for the last three years' Perriers, and when the administration deemed him too famous to be eligible this year, his promoters, Avalon, complained of bias. A weird storm in a pint glass resulted, with the Perrier people arguing that Murray was a star and Avalon arguing that he wasn't.

The Pub Landlord is no longer barred, although I don't know why he should care. For five years he has been getting reviews that many a Perrier winner would swap their trophy for. And here's another one. The Landlord - a demonic but endearing shaven-headed xenophobe - is a magnificent work of comedic art. The show is so richly layered and overflowing with ideas that it can seem as tightly scripted as any play; so organic and responsive to the audience that it can seem entirely improvised.

At bottom, it's a premium-beer barrel of laughs - and one that never needs changing. I'd seen two previous full-length Pub Landlord shows and I hadn't heard any of the material in this year's 90-minute set. What's more, he deserves some sort of award just for keeping going while necking three pints of beer. Al Murray: stays sharp to the bottom of the glass.

Rich Hall was a Perrier runner-up in 1996 and did a routine about his disappointment at losing the following year. This time he appears as his shambling alter ego, Otis Lee Crenshaw, a repeat offender from Tennessee - "Darwin's rewind button" - who has been married six times to women named Brenda. Backed by a two-piece band, he advises us on love and life, and plays us his hardbitten country tunes, including "Rodeo Man ... From the Shetland Islands" and a bold attempt to do for the Vauxhall Cavalier what other songs have already done for the Ford Mustang and the Deuce Coupe.

Hall is a natural. Not only did he get a laugh before he reached the stage, he got it simply by informing us that we could order drinks from the venue's waiting staff during the show. There's no explaining a gift like that, but it must help that Hall has a mischievous twinkle in his eye - even when singing a ballad about prison rape. He benefits, too, from a distinct facial and vocal resemblance to Yoda after a bottle of Jack Daniel's.

On to the Perrier Newcomers' Award. Last year Julian Barratt and Noel Fielding won it for their surreal pantomime, The Mighty Boosh. This year's sequel, The Arctic Boosh, is even better. It's the story of two postmen who are at the mercy of a monstrous Jiffy bag until they find a 10,000- year-old magic egg in the Arctic tundra, fall in love with a Yeti and ... you get the point. Or rather, you don't, because there isn't one except for pure, nonsensical fun. The lunacy never gets tiresome, though, because it's performed with unwavering conviction by Fielding and Barratt (who has the Yorkshire accent, the hair, the physique and the twitchiness of Jarvis Cocker). Both men are touched by genius.

Jon Reed's wired, psychedelic show makes The Arctic Boosh seem comprehensible. If I tell you that the climax is a short film about a football match between some Nazi clocks and Freddie Mercury, you'll understand if I leave it at that. Reed was shortlisted for last year's Best Newcomer award. It's easy to see why he was considered for that category rather than the main one. His show is so original and weird that he deserves to be encouraged, but as yet his chaotic ideas haven't quite gelled into a whole.

It's less easy to account for the inclusion of Chris Addison on last year's Newcomers' shortlist. Addison is a genial anecdotalist, but he has a nastily self-congratulatory streak. Besides, your "early-late twenties" is still too old to be fixated on the results you needed to get into university. Before Addison does another show, he should get out and see a bit more life. If nothing else, he should see Al Murray's show.

Also operating in the arena of cheery, twentysomething chat, but doing so more skilfully, is Adam Bloom, a motorminded motormouth with an irresistible Tiggerish positivity. As his material comprises the philosophical musings that buzz through his weirdly enquiring mind, one can't help but think how lucky it is that he's a professional stand-up. If he worked in an office, he'd be annoying his co-workers on a daily basis by asking them, say, whether you can make your girlfriend imagine that she needs you by sticking Nicorette patches on her while she's asleep.

For an alternative to alternative comedy, turn to the shows of the Nimmo Twins or Tim Vine. For all the absurdity of Vine's act, it consists, essentially, of puns which could have fitted into a comedy revue half a century ago if only they had "I say, I say, I say" in front of them. "I bought an American footballer," he says. "I paid a dollar and got a quarterback." And there's 900 more where that one came from. Vine has fallen on hard times since he won Best Newcomer in 1995 - he's been presenting game shows on Channel 5 - but his performance is a feelgood delight. Imagine the spirit of Eric Morecambe in the body of, well, Tim Vine.

The Nimmo Twins (naturally, there are three of them) perform sketches that could have been written by Ronnie Barker. The concepts are hardly groundbreaking, but they're painstakingly developed. In the post-Fast Show era, you have to admire the craftsmanship - and memory - required to recite a five-minute monologue built on the notion that medieval conquerors might pronounce words as they were written in the period, with "f" for "s". Unsurprisingly, the word "succour" came up quite a lot.

All shows: Pleasance (0131 556 6550), to 30 August