I think the US probably has the best variety/selection of food, although that is really only true for a fairly small percentage of the country (having done roadtrips where the choice is mcdonald's or chili's in every town for 100 miles convinces me of this). I think many other countries have a specific cuisine better than you can get it here. I think high-end dining (3* Michelin type stuff) is leagues better in Europe and Japan than it is here.

But boy do we kick everyone elses' rear ends when it comes to cocktails. I think we're years and years ahead of everyone else on the cocktail front-- knowledge, heritage, variety, skilled staff, cost of raw ingredients and finished drinks. Yum.