Okay, I can really vent on this one.
My worst one would be the most recent one- (or not shall I say 
) It was Madonna's Drowned World Tour. I spent an hour an half on line like 2 months in advance to get tickets (which I finally did) 120 dollars. The day she was to perform Friday at the Continental Arena I was out getting ready. Bought a new outfit and on and on. Anyway, I was on my way back home like 3 hours away from the concert starting and I get a freakin phone call from my husband who says it's CANCELLED. 
At first I didn't believe him and thought he was playing a joke. But go figure it did cancel. Humph. I still have the freakin tickets on my fridge. I could even scan them for you guys. Terrible right? Damn I was pissed. And still am to this day! Grrrrr. 