I've been rooting for Japan (since Canada didn't make it to World Cup this year - big surprise! *sarcasm intended*). Not only did they win their first game ever in the world cup on foreign soil, but they won 2 games and go second in their grouping!
I'm also really impressed with how well the U.S. is doing. They're sure holding their own with England in their group.
Cheers to South Korea, too!