I love watching all sports but football (soccer) is by far the best.
Its all non-stop. Yes of course it can be boring at times, but which sport isn't. I mean you can't tell me american football, baseball and basketball is always exciting to watch. Also skill level in football is higher just because you use your feet to control the ball. Everyone can use their hands, your co-ordination and control of your hands comes naturally to pretty much everyone because you eat, write etc with them. You only really use your feet for walking so to train them to have total control of a ball is harder.
The more popular american sports seem to be more focused on strength and overall atheleticism rather than skill.
Also why are there so much dead time in american sports. Players should be required to think more for themselves. In the NBA if a team is in the middle of a 13 to 0 run the opposition coach calls a time out to stop their momentum and tell his players what they should change in their approach. In football if a team takes a 2-0 lead after 20mins then its the players on the pitch who have to react and change the course of the game. Of course the coach can shout instructions from the bench but he cant stop the game. Players in football are required to be much more tactically aware.
As I said I love all sports. I can watch 9 innings of baseball, 4 quarters of NFL or 90 mins of football and enjoy them all. I just feel overall football is the most skillful and complete sport.