Best example of obnoxious: Repeating "Da Bears" every fall Sunday for the past 20+ years.
For the record, I'm a fan of the Chicago Bears, and yet I can see the annoyances with our base through friends and relatives, which is why I watch every game by myself with my cell phone turned off. Everything's the end of the world. Just take this season. Week One, tough loss to Buffalo, all week call radio and the paper were littered with comments about how this team sucks. Week two, win over San Francisco, all week call radio and the paper were littered with comments about how Seattle had better look over their shoulder. Chicago doesn't give a damn about anything besides the Bears and so it's either fans constantly feeling bad for themselves after every loss, or shouting about the Super Bowl after every quick start.