So, what do you think are the hardest sports for officials to do there job correctly in? With all the new instant replay being added to some sports, you have to consider that as part of the officiating as well (Which makes it somewhat easier, in my opinion)
My list would go like:
1. NHL/hockey (Speed of the game in general)
2. Basketball (Speed of the game, rules being applied differently at different times)
3. Soccer (Mainly because of the acting/flopping epidemic, hard to tell when something really goes on)
4. NFL/American Football. (Speed, lots to look at)
5. Baseball (Balls and strikes)
6. Baseball (everything else)
I don't watch enough of any other sport to have an opinion on them. This is not about the sport itself, but the officiating, so please don't start bashing something just because you don't care for the sport :P