We've had Leonard's lactose intolerance gags, Sheldon's 'spot', Raj's inability to speak to women without alcohol, Howard's Jewish heritage jokes, and an enormous wave of BAZINGAs throughout the series, it's time we saw something new. I don't have THE idea, but it would be great to see a joke that played a part in storylines over a few episodes or even longer. How I Met Your Mother had 'the pineapple incident' and 'the slutty pumpkin.' It needs to be a long-running gag that would freshen up the show and make it relevant once again.