A few months ago 20/20 had a segment featuring 10 yuppie, "vodka snobs" in their mid-to-late 20s who mostly swore by Grey Goose. They did a blind tasting panel and most of them unknowingly chose Smirnoff (triple distilled) as the best tasting one while heavily criticizing the Grey Goose and Belvedere. I keep a bottle of the Smirnoff triple distilled (1.75L for $13 at Costco) in my freezer and it's great for any mixed drink. Stoli is also very good for the money IMO.
GG's marketing is genious and have convinced millions of people to spend 3-times as much on their product than other brands of similar quality. You see the GG label and your brain tells you it tastes good even before it gets to your mouth. Most of the U.S. has the "label whore" mentality and overpay just in hopes of portraying an image to others.