The best of the best is usually based on ratings by professional tasters.  An example of one of the best is the Saint-Emilion Grand Cru, a Cabernet Sauvignon from Saint-Emilion, a commune in the Bordeaux region of France.
assitant
I can list top-selling red wines from various well-regarded brands, and also suggest others that have been reviewed by experts.
assistant
Where can I find the best tasting wine?
user
What sorts of wines are you interested in?
assistant
Red wine
user
Do you have a favorite brand, or do you want a generic recommendation?  I can tell you which wines from major global winemakers are considered very good and among the best tasting.
assistant
which wines are considered very good?
user