If someone has done something highly irritating or surprising in an exasperating fashion, you might say that they’ve “taken the biscuit.”

“Taking the biscuit” is the equivalent of taking the nonexistent medal for foolishness or incredulity.

“I could just about deal with the dog barking at 5:30a.m., but the lawnmower at 3 a.m. really takes the biscuit.”