There is no "winning country" in the Olympics. The games celebrate human achievement not national achievement. That being said, the US has won the most medals overall in all of the Olympics, Canada may well have won the most Gold Medals in a Winter Olympics and the US may well have won the most medals of any type in any of the Winter Olympics. I don't know which country has won the most Golds and most medals overall in the Summer Olympics.
The USA because they had the most medals and gold medals.
Canada won most gold medals (14) overall in the 2010 Winter Olympics in Vancouver.
The previous record for gold medals by the host country was 10. The previous best for gold medals at the winter games, host or not, was 13 by Norway and Russia.
So far the US won gold medals in certain events during the 2012 Olympics, but as to which country will win the most medals overall, that cannot be determined as of now.
Norway with 13 gold medals.
U.S.A. The United States has won the most overall medals. More specifically, the gold, silver, and bronze medals in the summer and winter games combined. However, Norway has outperformed the United States in the winter Olympics overall.
The country with the most gold medals at the Rio 2016 Olympics was the United States with 46 total.
462
Germany had the most gold medals at the 2006 Winter Olympics with 11.
At the 2008 Olympics, Russia won 23 gold medals and a total of 72, in third place overall behind the US (110 medals, 36 gold) and China (100 medals, 51 gold).
America had the most gold medals as well as the most overall medals.