The 2006 Cos d'Estournel is a Bordeaux blend produced in the St Estephe region of Bordeaux, France. This vintage, composed of 78% Cabernet Sauvignon, 20% Merlot, and 2% Petit Verdot, is noted for its opulence and complexity, as highlighted by several professional wine reviewers.

Wine Enthusiast rates this wine highly at 95 points, praising its ability to soften the traditionally austere Saint-Estèphe tannins into a wine of "opulence and roundness," with a "freshness of sweet homemade plum jam." Jeff Leve echoes this sentiment, also awarding it 95 points, and describes it as a "firm, crisp, classic-styled vintage" with "deep, dark red, and black fruits" and a strong tannin structure promising longevity until 2050.

Robert Parker's Wine Advocate, giving it a 94-point score, highlights the enticing aromas of "rosemary-crusted roast lamb, dried cherries, baked blackcurrants," and a "firm backbone of chewy tannins" that support a long, mineral-laden finish. Decanter provides a 93-point review, noting the wine's "firm cassis fruit" and "hints of tertiary notes," suggesting a complex evolution over time.

Wine Spectator and James Suckling both rate the wine at 92 points. Wine Spectator describes it as "racy" and "fresh," with flavors of "red currant and bitter cherry," while noting the presence of "slightly grainy" tannins. James Suckling identifies it as "meaty and spicy" with "chewy tannins" and a medium finish, indicating readiness for drinking now but with a future ahead.

Neal Martin's Wine Journal also awards a 92-point score, characterizing the wine as having an "opulent, gregarious nose" and a "full-bodied" palate with bold tannins that evoke a "daringly spicy and exotic" character.

In summary, the 2006 Cos d'Estournel is a well-regarded Bordeaux blend that balances strong tannins with rich fruit flavors and a hint of spice, promising a long drinking window.