There is an armchair centre- stage, but Hughes, a rheumy-eyed Stan Laurel look-alike with a London-Irish brogue, rarely sits in it, preferring to pace back and forth. His coat-hanger frame is slightly bent, as if his chin were glued to his left shoulder. His jokes are twisted too - turning back to have a gentle smirk at themselves before the punchline is out of sight. This doesn't make them less funny. 'I'm buying a house at the moment, so I've just had a survey done: 80 per cent of people said I should buy it' - a line worthy of Steve Martin at his most enduring. There's the odd cheap shot, though. If you're going to try and get laughs out of Linford Christie's genitalia, you might as well go all out and join the BNP.
Hughes' return to comedy basics will be doubly surprising to anyone devoted enough to have stumped up pounds 5 for the programme. This presents him as a cardigan-clad visionary of our era. It describes Sean's battles with Catholicism and his search for his true identity, culminating in a change of name (from John, which is not all that far from Sean when you stop to think about it). 'He lays himself on the line,' the writer observes, 'and we're not much used to that sort of honesty.'
Taking yourself too seriously is a common flaw among comedians. It only becomes a problem when it makes you hate your audience. Hughes seems to have been through this tunnel and come out the other side. He once threatened to play over-18s' venues only - on tonight's evidence he would need to book a bus shelter if he did - but now maintains an easy, avuncular rapport with his much younger fans. They certainly like him well enough. Hughes' brand of late-twenties bachelor angst ('How am I ever going to have a kid when I still wake up in the foetal position?') has its roots in adolescent self-absorption, but some of his best material has a real edge of adult darkness to it. When he pictures himself, 'at home, full of self-pity, masturbating into a jar', you can smell the crowd's fear.
He comes out for the second half as if refreshed with monkey gland. Picking up and dropping material seemingly at random, he gets scabrous and anal enough to shock teenagers. Unfortunately, he chooses to wash his creative dirty linen in public, too. Poetry is a new direction for Sean and, judging by the reception of his book - which has sold 20,000 copies in hardbook alone - a successful one. But that doesn't mean he is any good at it.
How can someone be so perceptive one minute and so totally blind to his own limitations the next? In showbusiness this is known as the Clive James Conundrum. Hughes' poetry-reading is a soul-curdling embarrassment. And a bizarre encore in which he mimes without any comic effect to bad, taped rock music reinforces the conclusion that in Sean's case, more is less.
After last year's three-month run at the Ambassadors, Eddie Izzard has pitched camp at the Albery, warming to his theme of West End theatres beginning with the letter A. In his choice of venue, as in many things, Izzard's judgement is sound. Theatres are better places for comedians to play than rock venues; not just for their own peace of mind but also for that of their audience, who get to feel cooler than a theatre crowd instead of less cool than a rock one. The only drawback is overcome with the magic words 'drinks may be taken into the auditorium'.
When I last saw Eddie Izzard, at the Shaw Theatre in 1992, his refusal to take television's quick route to household name-dom still seemed a bold gamble rather than a calculated career move. Ironically, it is easier to keep your mind on Izzard's comedy now he sports thigh-length Dick Whittington boots than when he was crammed into more mannish garb. He is much happier about using his body these days - before it seemed to be trying to escape from a stonewashed denim prison.
If all the awards and nominations have gone to his head, Izzard's performance does not show it. Success has made him more disciplined, not less. He hasn't curbed that rambling, manic digressive style - just tightened up the rhythm slightly, so at the end of this sparkling two-hour set he leaves you wanting more.
The freshness of Izzard's material is remarkable, not only for how quickly he rustles it up, but also for the familiarity of its ingredients: advertising; launderettes; the relative suavity of cats and dogs. In the hands of any other comedian this would be pretty stale fare, but he soars off from these well-worn launch pads on breathtaking flights of fancy. Izzard's riffs - the joy of turning on in-car heating at exactly the right moment, a small dog who's not satisfied with his wash - can be mundane or mildly surreal. It's the grace with which he handles them that makes him such an exhilarating performer.
When he pulls up in mid-flow, there is the same sense you get with Robin Williams sometimes, of the audience racing to catch up with a mind that moves too quickly for them. Only rarely does Izzard's fluid wit solidify into quotable shapes (on a supermarket dilemma: 'One jam is made by Nazis out of mud and twigs, the other is made by rabbits out of fruit that agreed to be in it'). The hallmark of his comedy is a kind of hyperactive anthropomorphism - through which characters and voices ranging from Roger Moore to Stanley Holloway can be assigned with equal assurance to huskies, flecks of falling fluff or a blue item of underwear in a white washload.
One of the things that makes Izzard stand out from his contemporaries is the relative absence of malice. This might be why his show's most affecting moments come when he finally uses his talents in anger. Turning on those who hunt in packs in search of women - or men in women's clothes - to harass and humiliate, Izzard observes, 'Why do these people always go around in groups of five? Perhaps it's because they've only got a fifth of a personality.'
Eddie Izzard, Albery, 071-867 1115, to 19 Mar. Sean Hughes, Croydon Fairfield Halls, 081-688 9291, tonight; Northampton Derngate, 0604 24811, Mon; Cheltenham Town Hall, 0242 523690, Tues; St Albans Arena, 0727 844488, Wed; Canterbury Marlowe, 0227 757246, Thurs; High Wycombe Swan, 0494 512000, Fri; Oxford Apollo, 0865 244544, Sat; then touring.