I could dig out the slides with fog, but they were "toss" shots partly because of the fogging. Not sure where they are, and frankly don't care about them. Someday, they will go in the trash (when I finally clean out the closet with decades of travel photos). The most egregious experience I had with x-ray damage was over 10 years ago when I travelled to Bulgaria and Romania shortly after the end of the Soviet Bloc. My films were all carried in my hand luggage, but we went through well more than 8 x-ray checks. Can't remember just how many it actually was, but quite a few. During that trip I had some of my films hand checked at some points, which probably helped me retain some "keepers" from that trip. I didn't notice at the time, but the higher ISO films (Ektachrome 400, some pushed) suffered the most.
I should say that I'm not trying to raise the panic flag here. Modern x-ray machines (at carry on points!!!) are not likely to fog average speed films with just a couple passes. All of my domestic travel that had films go through the carry-on machines has been fine (or at least I haven't been able to detect damage). I think that's because of both the modern machines, and the relatively few passes the film takes through them.
Also, I've found that all the busy airports within the U.S. will simply refuse to hand check your film...often with some nasty treatment when I ask. However, small airports are often really friendly and happily check my film (and chat with me about photography while doing it). I found airports in Ireland were friendly and happy to check film, but London really gave me the stinkeye. Prague was not friendly either. Most airports in Mexico were quite friendly except Mexico City.