One thing that really bothers me is when people call the field a "pitch."
People just don't get that some things are more Britishisms than they are soccer terms. Like, we're still Americans, you guys. We don't need to speak like British pieces of crap just because they like soccer more in their country....
Really though, my biggest pet peeve is when people exchange "is" for "are." Like "Sporting Kansas City are going to win." NO. If you're American, it's "Sporting Kansas City IS going to win." You sound like a Euro-snob if you talk like that.