For me, it has to be Never Say Goodbye at Hyde Park on the Bounce tour. It was just the way Jon said "we've been playing for three hours and I'm still going" then launched into it as the perfect end to a brilliant summer tour. It was the first time I'd heard them play it, and it was brilliant. Close 2nd is I Believe in Amsterdam from the same tour, and 3rd is I'll Be There For You at Hampen for OWN, because the atmosphere was just so electric.