Jenn--
In 2002, I saw a game in every MLB stadium in the country. (No I'm not kidding.) And based on that experience, I'm going to have to disagree with you. There are many teams that have much more obnoxious fans than the Yankees. Although they had some close competitors, the worst I ran into (on a whole) were those of the Oakland A's. And the worst individual fan I saw was actually a Padres fan.
The Yankee fans I met were actually very helpful and cordial. (And they were even playing the Red Sox the day I saw them!)
Their ushers and staff, on the other hand, were far and away the worst in baseball. In fact, I have trouble believing any team in any sport anywhere has fan assitance staff worse than these people.
Granted, I'm basing my opinions not on any team's "fans" in general around the country, but just those that happened to be at the stadium the day I was there. Still, I think it was an accuarate enough feel to say that both Red Sox and Yankees fans get an unfair bad rap...
--Bill