You can argue for hours about the singular flavors in a spectacular single malt whiskey or a good glass of wine. Vodka is different. This drink is judged not so much by its flavor as by its lack of flavor.

Reasonably sophisticated palates can tell the difference between a cheap vodka and a beautiful, silken shot of clear spirits that deserves to be quaffed all by itself from an ice-cold shot glass.

But most bartenders will tell you that vodka's surge in popularity in recent years can be attributed more to its qualities as an empty canvas than to all those new premium brands on the market.

Don't get me wrong - most of those high-priced vodkas are very good, and some are truly excellent. But the big story in vodka these days is flavor. In some ways, vodka is the canola oil of the spirit world - the perfect vehicle to carry and enhance other flavors. So perfect, in fact, that the venerable martini is now virtually unrecognizable to fans of that symbol of the traditional American cocktail hour.

But if the cocktail hour is quintessentially American, so too are all those new, offbeat versions of the old standby of vodka (or gin) and vermouth. After all, innovation and experimentation are as American as the martini.

"This is a country where trends are very important," says David van de Velde, president of Van Gogh Vodkas, a Dutch distiller that produces high-quality flavored vodkas, as well as a top-notch vodka and gin.

When drinking preferences turned to lighter-colored spirits about a decade ago, vodka became the inspiration for a burst of creativity. These days, no ambitious bar would open for business without significant shelf space devoted to a range of flavored vodkas. And savvy bartenders can mix up an "appletini" as easily as a vodka and tonic.

The most common flavored vodkas are citrus - and no wonder. The citrus is strong enough to infuse the vodka easily, and the combination saves you the trouble of adding a twist of lemon or lime to your drink.

But subtler flavors are a different kind of challenge, especially since a flavored vodka can contain only a limited amount of added sugar to retain the vodka label.

Van de Velde says the company's best-selling flavored vodka is Wild Appel. Most attempts at good apple-flavored vodkas have failed because most apples have too much sugar. Van de Velde hit upon the idea of using wild apples, which are smaller and less sweet than the fruit from well-kept orchards. The result is a more intense apple flavor with less sugar. It's the perfect base for an appletini.

But my vote for the most intriguing and adventurous flavored vodka goes to Van Gogh's Dutch Chocolate Vodka. Van de Velde says the company starts with a good, strong Dutch chocolate, cuts it in chunks and lets it sit for six weeks in an underground vat with 196-proof alcohol.

The two ingredients "marry," then the alcohol is drained off, mixed with water and redistilled. This chocolate distillate is then mixed with Van Gogh Vodka.

The process is time-consuming and complex enough that the vodka is made only in small batches. But it produces a smooth vodka with a distinct chocolate flavor and only enough sweetness to prevent a bitter taste. It's a fine drink all by itself. But for a festive drink, combine it with Van Gogh's Amsterdam Chocolate Liqueur, or some other chocolate liqueur, and make a martini to remember - a chocolate martini.

Chocolate Martini

Makes 1 serving

2 ounces Van Gogh Dutch Chocolate Vodka

1 1/2 ounces Amsterdam Chocolate Liqueur

shaved chocolate

Combine first two ingredients over ice in rocks glass. Strain into glass. Sprinkle with shaved chocolate.

The Dutch Godmother

Makes 1 serving

2 ounces Van Gogh Dutch Chocolate Vodka

1 ounce amaretto

chocolate-covered cherry

Combine first two ingredients over ice in rocks glass. Serve with a chocolate-covered cherry.