Mine would probably have to be Death From Above 1979 at reading festival 2 years ago, who i missed to watch Graham bloody Coxon on the main stage. Not that i dont like Coxon, its that i thought at the time i could see DFA 1979 anytime and Coxon would be someone you would see once in a blue moon. How little i knew.
A story will stay in memory was my house mate who told me once how he missed out on seeing McLusky at the Square in Harlow. Supported by a then unknown band called The Libertines.