By Lenn Thompson, Editor-in-Chief Rich Pisacano, co-owner of Roanoke Vineyards, is a cabernet sauvignon guy, and he and consulting winemaker Roman Roth make some of Long Island's most consistently good cabernet-based wines — no small feat in a cool climate region. But as good as those cabernets can be, this is still Long Island, where merlot still rules. Not surprisingly, the Roanoke Vineyards merlots can be standouts as well. Even in its youth, this Roanoke Vineyards 2005 Merlot ($45/sold out) shows depth and complexity on a nose where black plum, blackberry and blueberry fruit aromas mingle with those of licorice,…