To paraphrase Irving Berlin, the best things happen when you're drinking.

Eavesdropping, for instance. So I'm nursing a margarita in the bar at Masa when the two women to my right start talking restaurants, praising and skewering the latest and greatest. Their views and mine barely converge, in that were-we-eating-in-the-same-restaurant? way.

"What have you heard about that Barrio place down the street?" one asked the other. The response was a shoulder shrug, followed by a somewhat dismissive, "I hear that it's a bar with food." It was all I could do to bite my butt-insky tongue, because what I wanted to say was, "You're half right. It's a very good bar, with very good food, if you ask me." Fortunately for them, they didn't.

Co-owners Tim McKee and Josh Thoma certainly read the market right when they opened this champ, their fourth collaboration following La Belle Vie, Solera and Smalley's Caribbean Barbeque and Pirate Bar. Talk about prescience. Just as Barrio's doors opened, the economy tanked and suddenly it seemed as if anyone with a Gold Card was trading their high-end dining habits for cheaper, more casual alternatives. The kind Barrio just happens to offer. In spades.

Much of the restaurant's appeal rises from a one-two personnel punch. Bill Fairbanks, a longtime La Belle Vie sous chef, is making magic in his square foot-challenged kitchen, guided, no doubt, by McKee's limitless imagination. Company mix master Johnny Michaels -- he's the expert who makes the LBV lounge the city's top cocktail destination -- is responsible for Barrio's crazy-good libations.

Fairbanks first. He takes staples of the Mexican chain-restaurant stable -- tacos, enchiladas, tostadas, each beaten down by the Taco Bells and Don Pablo's of the world -- and breathes invigorating new life into them through a potent blend of ingenuity, enthusiasm, cooking prowess and impeccable ingredients.

Take your pick

The menu isn't large, but it's remarkably coherent. There's not a misstep in the bunch, and very little overlap, meaning you won't find the same fallback salsa or pico de gallo lazily blanketing every plate. In fact, I can imagine a substantial number of curiosity seekers going just to explore the splendid variety of salsas.

It's funny saying this about a taco, but Fairbanks' mahi-mahi version is rapturously good, the succulent fish enrobed in a gossamer beer-batter tempura and paired with a cool cucumber pico de gallo. I love the robust red chile enchilada, flecked with a peppy chorizo and topped with a gently fried egg. Cinnamon-kissed carnitas is served two ways, either as a taco (with an excellent serrano salsa) or crowning a pair of sopas and finished in a rich ancho-tamarind sauce. Both are heavenly. Ditto the shrimp tacos, their feistiness balanced by a grilled tomato-mint salsa, and the chicken enchilada pretty much shows how the genre is done.

Other don't-miss dishes? The grilled shrimp, skewered on sugar cane. The tequila-cured gravlax. The lovely jicama-citrus-pepita salad. The brightly flavored scallop-grapefruit ceviche. The golden empanadas, liberally stuffed with crab. The complex soups (although the one major glitch I encountered was an alarmingly past-its-prime crab soup).

Heck, even the guacamole is an event. It's a mash of avocados so creamy you'll wonder if you should eat it or save it for a facial mask. Peppered with coin-cut radishes, snips of jalapeño, cilantro leaves and the faint, teasing trace of cumin, it's served with a bowl of addicting, salt- and cumin-dusted tortilla chips. Just thinking about it makes me want to double-park somewhere near 9th and Nicollet and dive into an order. Right this minute.

After all those glorious small plates, the menu's half-dozen entrees seem a bit superfluous. They're fine -- more than fine, actually. Best are the plump shrimp with zesty citrus-pepper accents, the moist steamed mahi mahi, a juicy pan-roasted chicken doused in a spirited chimichurri, and meaty pork ribs, cured with ancho and chipotle chiles and marinated in an intense tamarind-roasted tomato sauce. Still, their hefty portions put the brakes on the restaurant's brisk grazer's pace, and it makes me wonder what else Fairbanks could do if he dropped the big plates and added more small ones. Bumping up the fabulous beef tongue tacos from daily special status to a regular berth on the menu would be a step in the right direction.

Lively and lovely looks

The storefront space, a throwback to Nicollet's days as a shopping juggernaut, embodies a basic Event Planning 101 maxim: Squeeze a maximum number of people into a minimum amount of real estate. The much mellower lunch-hour aside, I can't recall dropping in and not encountering an elbow-to-elbow crush of pretty people, boozing, noshing, flirting, laughing and setting aside, if only for an hour or two, the woes of the world.

Shea Inc., the Minneapolis design firm, installed big glass doors that nicely blur the boundary between sidewalk and restaurant. Flickering candlelight and scene-setting visual quirks set the tone, including a trio of amusing live-action marionettes that were plucked off eBay at nine bucks a pop, a stunner of a graffiti-style mural painted by Juxtaposition Arts of Minneapolis (look closely for the abstractions of bulls one-upping matadors) and a dramatic candelabra accumulating so much dripped wax that it has quickly taken on an eerie, separated-at-birth resemblance to the Minneapolis Institute of Art's "jade mountain" Chinese carving.

Two flaws: A single front door translates into frequent and massive blasts of frigid air, and a seat on the claustrophobic mezzanine is the equivalent of being relegated to the kids' table while the grown-ups eat downstairs.

The bar is a tequila-lover's dream, boasting an inventory that tops 100 varieties; buy them by the shot (hello, sticker shock), mix them with tangy house-made sodas or enjoy them in a standout roster of margaritas and cocktails. Michaels also showers his alcohol-free mocktails with similar creativity and care -- minus the hooch -- a touch that this occasional drinker really appreciates. But that's Barrio, which doesn't seem to miss a trick.

"What do you think these guys will do next?" I asked my friends as we eased into our second round of margaritas. Then I looked around and thought, hmm, maybe the people sitting next to us know the answer, or would be willing to venture an opinion.