take the biscuit
From Longman Dictionary of Contemporary Englishtake the biscuittake the biscuitBritish English informalSURPRISED to be the most surprising, annoying etc thing you have ever heard SYN take the cake especially American English I’ve heard some excuses, but this really takes the biscuit! → biscuitExamples from the Corpustake the biscuit• Now this just took the biscuit.• This really takes the biscuit!!• Clive Anderson O, while the mighty Sultans take the biscuit.