The great wines of the world are expensive and often hard to find. They are also, in many ways, unmistakable—in much the same way a movie star is instantly recognizable on-screen, the stars of the wine world are (or should be) instantly recognizable in a glass. At the same time, part of what makes a great wine great is how well it expresses something larger than itself: the region of origin, the grape variety or varieties, the character of the vineyard, the tradition behind the wine.
This is why it is possible to find—if you look hard enough—affordable wines that echo the characteristics of the truly extraordinary. A terrific $15 Côtes-du-Rhône from an obscure property (or even from a well-known property) may never achieve the complexity, depth and nuance of a top-level Châteauneuf-du-Pape, but at the same time it can offer a hint, or more than a hint, of what that much more expensive wine from the same general region is like. Similarly, a superlative Australian Shiraz may offer far more richness and intensity than a very good $15 bottle, but at the same time the two wines may share certain flavors: ripe blackberries, say, with a subtle vanilla note from the oak barrels that both were aged in.
One trick for finding these bargains is to hunt for famous grapes in unsung bottlings. In Burgundy, for instance, grapes from grand cru or premier cru vineyards are occasionally "declassified" when their quality doesn't quite live up to expectations. But when those grapes are blended into a basic and relatively inexpensive Bourgogne Blanc, the quality of the lesser wine can go through the roof. (Visiting the Web site of a good producer—or even better, a good importer—sometimes provides this information.) Keeping track of current trends also helps. In Bordeaux, for instance, thanks to ambitious investments and attention from some of the top winemakers in the world, formerly disregarded regions such as the Côtes de Castillon, Fronsac and the Côtes de Blaye are now producing surprising numbers of high-quality wines that capture some of the qualities of the most revered Bordeaux bottlings, and they're priced without the upcharge that more illustrious regions ask for. And noticing when a winemaker or winery famous for making world-class, cult Pinot Noir, say, starts a new, affordable brand as a side venture is always a good strategy.