i walked out on sonic youth back in '99
got caught sawing logs at a radiohead show. (it was one of the few gigs they did in support of "Kid A" man, did i get a talkin' to from the ex for that one)
walked outta a tori lame-os show when me and the ex (she wanted to see her again for the 7th time) got into a nasty row
walked out on the yeah yeah yeahs because they could get through one tune properly
walked out on sigur-ros because if you've seen an icelandic contra tenor bow a guitar once, it is about half as stimulating when he does it again.
was forced to walk outta two pinback shows (local boys) before they started doing much on a national level. the ex was pissed off about something and didn't give two fucks about them. now she has become super-fan and swears that she never went to see them when they had started.
walked out on a few album leaf gigs too, but that is only because i've seen jimmy and the boys do their thing more than i can count on my hands. its gotten to the point where it is just fun to grab a beer and heckle them...