Not that it counted for much, but I guess two things. When going to catch a legendary, I had Hypnosis on my Gardevoir and it missed 10 times in a row, only one of those times was due to Safeguard from the legendary, but the damn thing kept missing.
Also during the 8th gym against Cryogonal, using an Aegislash, it used Confuse Ray a few times but in that confusion I hit myself five times in a row and it froze me twice on 3 or 4 Ice Beams. (1/2)^5 anyone? A little over 3% chance, not including the freezing.