It is a truism that the bar, the pub, the tavern, the alehouse, the local, the watering-hole and the seedy dive collectively exert an influence over human culture that cannot wholly be explained by the lure of alcohol. We are drawn to the lights, the painted sign, the hubbub and (for now) the smoke, like pilgrims to a shrine, to be welcomed into a communion of souls; flushed, exultant, temporarily absolved of our sins. To see the bar or pub as a church is, of course, nothing new. William Blake's "Little Vagabond" in the Songs of Experience made a good case for turning the latter into the former:

Dear mother, dear mother, the Church is cold;

But the Alehouse is healthy, and pleasant, and warm.

Besides, I can tell where I am used well;

Such usage in heaven will never do well.

But, if at the Church they would give us some ale,

And a pleasant fire our souls to regale,

We'd sing and we'd pray all the livelong day,

Nor ever once wish from the Church to stray.

Warmth and health were the constituents the child most favoured in a bar (health presumably because it was unsafe to drink the water in 1795 London). A third virtue was celebrated elsewhere in London 20 years earlier by the greatest saloon-bar moralist of the Enlightenment: "There is nothing which has yet been contrived by man, by which so much happiness is produced as by a good tavern or inn." Given the happy inventions that human society had devised by the 1770s (flushing toilets, steam engines, false teeth, printing presses) Dr Johnson's claim was considerable. Today, two centuries later, the bar is the key location of our collective sense of self; it's our scaled-down version of the Roman forum and the Greek agora, a place of meeting, discussion and ad hoc law-giving, only with added beer. Bars are still places of warmth, health and happiness, but they're more than that. They exist not just to satisfy a craving for thirst, as a restaurant services a craving for food; they transcend the immediate need; they encourage conversation, revelation, connection and stirrings of love. They're also places of competition, dissent, displays of braggadocio and drink-fuelled mayhem. No wonder they bulk so large in our popular culture.

The UK's two most popular TV shows have a pub at the centre of the action: the Rover's Return and the Queen Victoria, where the glum burghers of Salford and Walford congregate to carp and scheme and flirt. In the US, a vestigial Mayflower puritanism kept soap operas away from drinking holes until the 1980s when NBC took a chance on Cheers. It was OK, it seemed, to set the action in a boozer provided the barman was a former baseball hero with a complicated love life; in the 1990s, it was just-about-OK to show the cast of a comedy drama visiting the bar in every episode, provided they went there to sing show tunes: remember Ally McBeal?

Movie bars have, for nearly a century, been the melancholy backdrop of bittersweet emotions. The greatest love story from the war years is set in Rick's "Café Américain" in Morocco, complete with black piano player and sultry collaborationist barfly. Classic film noirs took their titles from glam-but-rackety bars like The Blue Dahlia. When movie audiences flocked to hear Greta Garbo's first words in Anna Christie in 1930, what did they find? Their heroine stumbling into a waterfront bar, and slurring, "Gimme a visky - chinger ale on the side - and don' be stingy, baby ... "

It's not hard to understand their popularity on celluloid. On-screen, the warm lights and dark shadows provide a perfect visual correlative to the optimism and despair of lovers and losers. As Edward Hopper knew, nothing bespeaks personal emptiness as bleakly as a bar at closing-time. Which thirty-something man can resist trying on the image of the bar-room romantic, nursing a bottle and a bruised heart like Humphrey Bogart in Casablanca?

In literature, the boozy loser in the fly-blown dive was to some extent invented by Ernest Hemingway, a ferocious real-life toper. His first novel The Sun Also Rises presented the pub-crawl as a kind of existential wayfaring: his small platoon of adventurers in postwar Paris and Pamplona moves from bar to bar, from drink to drink, as though in flight from the dilapidation of Europe - and on the run from their own impotence and accidie.

Hemingway's memoir of Paris in the 1920s, A Moveable Feast, offers a cosy litany of bar names: the Dome and Les Deux Magots, the Negre de Toulouse and the Rotonde, the Closerie des Lilas - names that recur like a mantra in any biography of the "lost generation", like the Stations of the Cross relocated to Montparnasse. A dim echo of this bar-room mythologising can be heard in histories of Fitzrovia, the area north of Oxford Street where London-based creative non-combatants (Dylan Thomas, Julian Maclaren-Ross, George Barker, W S Graham, Nina Hamnett, John Lehmann and the Sri Lankan conman-poet Tambimuttu) congregated during the Blitz years. The scabby pubs off Charlotte and Percy Street - the Wheatsheaf, the Fitzroy Tavern, the Grenadier, the Marquis of Granby - have today become places of pilgrimage for a generation of readers who swoon at the idea of an identifiable "Literary London", buying each other drinks and sponging fivers.

So the bar took its place in cultural history: as a smoky haven, a meeting-place, a habitat for the creative soul to nest in. But what makes a good bar good? For the Fitzrovians, it was hardly more than the presence of beer and each other; nobody ever went to the Wheatsheaf to enjoy the sophisticated décor. For the Americans in 1920s Paris it was something subtler - an atmosphere of welcome, conducive to both working and talking. For George Orwell, on the other hand, writing just after the Second World War, there was a whole exhaustive list of criteria to consider.

In the Evening Standard of 9 February 1946, he described his favourite public house, The Moon Under Water. It was located down a side-alley near a bus stop, a place unknown to "drunks and rowdies". The atmosphere, he explained, was more important than the beer: it had Victorian fittings, grained woodwork, ornamental mirrors, iron fireplaces, nicotine-stained ceilings. Games were played only in the public bar, and conversation was never disturbed by piano or radio. The middle-aged barmaids knew the regulars by name and called them "Dear" (but not "Ducky", which Orwell abhorred). You could buy cigarettes, tobacco, aspirin, stamps and bar snacks (but not dinner) at the Moon Under Water, which served his favourite draught stout which he drank in a pewter pot (he also seemed weirdly keen on strawberry-pink china mugs). The best thing about the pub, he thought, was the garden where, in summer, he would sit under the plane trees surrounded by families whose children disported themselves on swings.

Sadly, his ideal bar was, he revealed, a fiction, an idealised dream of everything he wanted. "If anyone knows of a pub," he wistfully concludes, "that has draught stout, open fires, cheap meals, a garden, motherly barmaids and no radio, I should be glad to hear of it, even though its name were as prosaic as the Red Lion or the Railway Arms."

I recognise his wistfulness. For years, my ideal pub was an Irish shebeen on the County Clare coast that I discovered when escaping from a rainstorm. I loved the melange of smells - of burning turf and spilt beer, mushroom soup and cigarette smoke, wet tweed slowly drying, and the dentist-waiting-room aroma of the cloves for the hot whiskeys. I also loved the way the musicians drifted in, to play fiddles and accordions as the evening lengthened. It was an embracing fog of fragrances, sound-tracked by the irresistible lilt of live music. It couldn't, of course, survive. These days, the chances of finding such a fug (or such a noise) have plummeted to zero. Now that, in most British cities, English pubs and American bars have melded into each other, now that the after-work culture of cocktails and "happy hours", the relaxation of drinking hours and the dreaded smoking ban have introduced a new relationship between bar and patrons, what makes the perfect watering-hole 60 years after Orwell's essay?

It's hard to generalise. How can you weigh the old-fashioned Victorian grace of a Kensington pub like the Windsor Castle against the crazy pan-Asian metallic friezes of the bar at trendy Gilgamesh in Camden? My criteria in trying to choose 101 recommendable bars around the world are a combination of the abstract and the concrete. They share very little with the Carlsberg commercial.

1. Welcome I like a bar to be instantly friendly, with no bouncers, velvet ropes, hostile looks, inspections of my eveningwear or other impertinences. I am coming into your premises to spend folding money on drinks and I expect you to say, "Hi there - so glad you could drop by. What'll you have?"

2. Shadows No harsh lighting (unless it's a dramatic effect to backlight the bottles of Scotch) and no 40-watt dim lighting, the sort you find in a J D Wetherspoons pub. I like lots of shadow in a bar, a crepuscular gloom wherein secrets and stories can be exchanged and no business done.

3. Surprise The good bar will shock you slightly as you walk in - with its lushness, its scale, its apparent antiquity, its profusion of artefacts, its boldness of design, the beauty of its bar staff, the torch singer at the piano, the white panther on a lead...

4. Temperature Not of the room (which will, obviously, be room temperature) but of the drinks. Your first mouthful of Sancerre should be stunningly cold, with beads of condensation coursing down the glass. The Romanée La Tâche, however, should not be stunningly warm, as if left on a radiator. It should be (duh!) the temperature of the room.

5. Interest It's better (isn't it?) to offer house-guests a living-room with stuff to look at rather than bare walls. I'm a sucker for bric-a-brac: dangling chairs, collections of tin cars or geisha fans, masks or sunglasses, ancient newspapers, Edwardian valentines, Georgian chamberpots, Victorian leech jars...

6. Food None. This is a bar, a place for drinking and modest carousing. Knives and forks and napkins, and things to slice up and ingest, have no place here. Oh all right, you can have a small bowl of Twiglets, but that's it. If you want your supper, go somewhere else.

7. Comprehensiveness A bar should stock all manner of obscure drinks in anticipation of the day you suddenly develop a craving for a Pimms No 6, a 12-year-old sloe gin, a Ketel One martini, a tequila-with-dead-earwig...

8. Banter Bar staff of either sex who chat, flirt, suggest little refinements you might enjoy ("Try this dribble of sherry over the cherry tomatoes on your Bloody Mary...") and take an interest in your plans for the evening are always welcome, in any country and any language.

9. Music No tinkling piano, no open-mike guitarist, no juke-box, and no cacophanous hip-hop from the speakers. We can allow some music, provided it's the staff's own choice of classic rock'n'roll, played at a volume modest enough not to disturb your train of thought/ conversation/marriage proposal.

10. Smoking I know, I know. But if, through some sad atavistic impulse, you absolutely crave a cigarette at 11pm, there should be somewhere on the premises you can enjoy one. An understanding barman with a strategic ashtray is a friend indeed.

And there you have it all: the warmth and happiness (though not necessarily the healthiness) of the perfect bar, just as Blake and Johnson imagined it. Cheers!