SFCU (sydney FC unnoficial) is probably the best forum. Victory forums are also good but you cant get on them these days unless your already a member. The World Game is definatly the biggest but its really poor quality, alot of talk notr elating to football, and also alot of NSL/A-league bitching. This forum has the friendliest people.
Sydney FC is the best chatroom as there aren't many tards. But in the old days when I used to browse the Victory forum, they had alot of news before the SFCU room did, it's just a pity i can't get on there anymore.
You need to get out more... SFCU seems to get more opposition supporters than the others... The World Game is good if you enjoy arguing.
There really isn't any good one, with lots of members and actual decent discussions. The World Game DOES have good discussions sometimes, but you have to wade through so much racism, porn postings and general crap that it's barely worth the effort.
ive posted a few times names iaco i think dont go on much only when the mvfc boys wanna start shit with the sydney boys.