I wouldn't say that I've really met one in the wild, as such...
I've met **Andy** on a day's caching, but I knew him from before, and it was arranged - So I don't think that counts.
I've also me MumboJumbo, but that was in a pub and was deliberate... Although I did watch him pick up two of my caches from a far (trying not to be seen - didn't want him to think I was a stalker)
I've met Pamina2006, although we introduced her to caching, and have known her for years, so doesn't count
I've also met Wisewol and HillHappy1 sort of in the field, but we were all hanging around after the coordinates on a cache were found to be incorrect...
I have yet to catch anyone red-handed, or be caught... perhaps one day soon.