Kaiser, you weren't accurate on this one. It's imposible to compare both because of a guy in the back throwing the ballon, because rugby's rules prohibit advancing the ball even an inch throwing it with your hand. In fact, that's the great difference. In american football, the game is based on passing the ball (hence the importance of quarterbacks), while in rugby you have to carry the ball, or kick it straight with your foot, and try to get it again yourself; any pass you make have to go back, or in the same line as you are. Then you don't have melee in american football, etc. There's many differences.
Anyways, both are crappy sports, soccer is the real deal

. Although basketball is pretty enjoyable, too.