personally i'm a fan of all three codes. although some of the rules in afl are pretty pathetic (melee, tackling, ball hitting the post not being play on), i like the way the game is run eg draft, trading, tv.
union is more of a tactical game. there's a lot more running of the ball than what there used to be, which is good. and scrums are a contest as well.
soccer is built on passion and skill. watching players like ronaldinho are henry show their talent is amazing. plus it brings out the best (and sometimes worst) in a fan.