Please, everybody, stop calling the the NFL, NBA and MLB champions the "World Champs." They aren't. They are, respectively, the champions of the NFL, the NBA and Major League Baseball. It's possible that each of them are the best team in the world in that sport that year, and in the NFL's case you could argue that since not a single other country in the world plays the game that they are de facto the World Champions (although it's still a little arrogant to call someone World Champs when the scope of the competition is just a single country) BUT, in the case of the NBA and MLB, it's just straight-up, 100% false.
But our baseball and basketball leagues are the best in the world! Who would argue that the best players don't all come here to play?
See - that's not quite the point, because the word "Champion" does not mean "arbitrarily chosen to be considered the best" (BCS boondogle not withstanding). A champion is defined as:
a person who has defeated all opponents in a competition or series of competitions, so as to hold first place
This is the problem - in order to have a champion of something, you sort of have to have a tournament for that thing. That being clear, I'd like to point out:
The NBA playoffs are not a championship all of the teams in the world are eligible to gain access to.
The World Series is nothing of the sort.
The Super Bowl features two teams from the US.
Although magnificent achievements, in none of those cases should the victor be assumed to have defeated all opponents in the world. So please stop it with the pro-US arrogance and call them what they are... the NFL champions, the NBA champions and the MLB champions.
And while you're at it, call the winner of the BCS title game what it is - the winner of the BCS title game. Let's stop granting sports victory titles by fiat.