The slow handclapping when players contest calls at Wimbledon really bugs me.
As an aside, I was listening on the car radio yesterday to Svitolina v Sviatek, and was infuriated by possibly the worst tennis - or even sports in general commentary I have ever heard. Marion Bartoli was the co-commentator and she wasn't the chief culprit: her colleague rarely described a point properly, or made it clear who had won it, and managed to talk over our only remaining hope of finding out: the umpire. At one point they were gossiping as a rally was in progress. When she was replaced: what a difference.
They'll never properly replace Max Roberston :-)