At this moment: Costa Rica vs. Serbia. (The match is lacking a spark; thus far.)
The most important match of the day, for me, is Germany vs. Mexico. That one plays out starting at 11:00am, my time.
And at 2:00pm, Brazil vs. Switzerland. While clearly the underdogs, the Swiss squad will probably come out kicking.
Post Note: It's so nice watching a World Cup match and not having to listen to those infernal giant bees.