I have tried Argentinian beef, Its is very flavorful, lean and tender. In comparison to USDA beef. Now, you can find the same quality beef here in the United States. You just have to pay a little more out of pocket. What you are looking for is free range grass fed black angus cattle. The black Angus cattle is a scottish breed and was introduced to Argentina 16th century. Most beef producers from Argentina raise their cattle in Las Pampas, a large and rich grasslands in central Argentina. The cattle are able to free range and eat nothing but grass.

If you do have a chance to travel to Argentina, do by all means. Try it first hand. And if the beef doesn't thrill you the culture and wine will. http://youtu.be/5d4l10P8g3M?hd=1

Also I do enjoy Kobe Beef from Kobe, Japan. However, it is very expensive. Usually out of my price range.