As passenger...
RTO at CDG in a BA 1-11 ( aaahhh ) late one Saturday evening in the late 70's...Speys spooling when suddenly thick black smoke poured through the vents....Immediate shutdown and down the slides, but with no more than 20 of us that night, all fairly undramatic....
GA at MIA in a PA 747 in the early 80's....Two attempts in heavy storms both had us over the zebras before Cap'n Thomas abandoned the third approach at about 1,000 feet and took us off to FLL instead....I've often wondered since if or just how much they had to strip off/out of the machine ( an old -100 ) to get it back out of FLL....
RTO at LHR about twelve or thirteen years ago in an IB 340....After pulling off to the left, an angry El Capitano came on the R/T and instructed everyone to check their mobiles were, indeed, switched off followed by a rather resigned comment that he would then need 90 minutes to allow the brakes to cool....
GA at MAD just a week later in a BA 737 from about 500 feet....No reason given....
In 9,000 hours and who knows how many Sectors, just one RTO - in CMN five years ago when at about 80 kts we suddenly saw the nose cone of our F27 detatch itself and vanish over the top of the fuselage....But far too many MA's to remember - probably most of them being ultra-cautious, but par for the course at small(ish) airfields here on the Dark Continent and so I never admit the blame for these....