i can't even think of another sport where the fans take the fighting onto the streets. just the other week rangers fans came into manchester for the eufa cup final, there were about 150,000 fans in total. the streets were blitzed with fans, I've never seen so many blue shirts in one place before. rangers ended up losing the game 2 - 0 and all hell broke lose. you should have seen thee city centre the next day, the streets were soaked with beer and piss. i was knee deep in empty beer cans and unconscious ranger fans.
heres a vid i found on youtube showing some of it
and the top 3 rivalries in sports are
1. manchester united vs manchester city
2. manchester united vs liverpool
3. manchester united vs arsenal