From my time in Melbourne (2000-2007), Collingwood fans were the one's I worried most about starting something for no reason (the game we just beat them it was head down and head out quickly without making eye contact with any), but Essendon were certainly the most arrogant. At the time I was there they were a successful club at the start of that period, having arguably the best VFL/AFL season ever in 2000. The arrogance didn't diminish over the years as they went to losing finals, then not making them. Though ironically the only attempt at starting a fight I did see was a fat Hawks fans after our match in 2004 at the MCG, trying to provoke people into a fight. Obviously hoping someone in a hawks top won something that day (no one was sucked in).Especially satisfying that it was Essendon and, in my case, being there to see it in person with my daughter, as we attended our first game for 4 years.
I'm sure there are some good people who support Essendon but in my years of living in Melbourne and going to games I've always found them to be the worst of all fan bases, effectively the Victorian equivalent of Adelaide and West Coast fans.