Australian Rules is played in Melbourne, Adelaide, Perth, Sydney and Queensland but is biggest in the first three cities I named.
Rugby League (RL) is played mainly in NSW and Queensland but there is a team in Melbourne too. I don't know why they call RL football when they mostly carry it and throw it.
Football, or Soccer as it is mostly called in Australia has a National League with teams in Queensland, NSW,Victoria, South Australia and Western Australia. Australia is 33rd in the world and probably second to Japan and maybe equal with South Korea in the Asian Confederation. At the moment Emile Heskey, Shinji Ono and and Alessandro Del Piero are playing in the A League. The A League is probably equivalent to lower League 1 upper League two in England. I have seen Australians in these league who would struggle to get a game in the A League but they make more money playing in England. Of the Asian league probably only J League is better, Australian sides have competed quite well in the Asian Champions League especially Adelaide United. I have seen Australian players in the K League and Chinese Super league who were only equal to the better players in Australia and some who would not be in any first 11 in any A League side.
Basketball has a National League with the same states participating as soccer and Australia has Andrew Bogut and Patrick Mills playing in the NBA. Australias national side is 10th in the world and made the last eight in the 2012 Olympics.
I was probably more of a fan of the Premier league in England than La Liga in Spain or Serie A in Italy but I know of the better players in those leagues.
There is a Scottish/Filipino playing in the A League at Adelaide United and his name is Iain Ramsay. I note there is a FilOz, name Leigh Gunn who is in the Azkals squad. He has played in the NSW Super league but I don't know how good he is. Obviously not as good as Ramsay because he plays in the ALeague and is potentially in Adelaides best 11 if he was more consistent.
Sport is a big pastime in Australia because people can afford to do it and we have superb weather to play outdoor sports and we do ok across the world. I suggest you go to an A League game in whatever city you are in and check out a game sometimes. Technically it could be much better but games are competitive and there are a few players who are quite good and im sure you would enjoy it.