~My Dragonite lost to a Geodude once...
I used ice beam, Geodude survived (God damn you, focous band!) and it used rock slide or something, critical hit, I die.
~My opponent's Heracross hung on with its focous band three times in a row, it cost me the match...
~Blisseys/Shuckles that spam double team and toxic, then use rest/softboiled really hax me. Once they have a single DT under their belt, my attacks are accustomed to miss on EVERY SINGLE TURN, even though their evaisioness is raised only one stage.
~In the battle factory, a Walrein OHKOed all my pokemon with sheer cold, it was so cheap, and the attack hit three times in a row, despite the 30 accuracy.
~In the Battle Dome, I always seem to encounter opponents with Ursarings or Snorlaxes that use mega kick on every turn, and it always critical hits!
~If my opponents use attacks like fire blast, thunder, hyper beam, ect., they seem to hit 95% of the time, while if I ever try to use lower accuracy moves, they pretty well always miss, and I end up lossing because of that. That's why I use '100' accuracy moves nowadays.
~In the Battle Pike, my opponent had a Jynx with Mean look, perish song, lovely kiss, and like ice beam or something. So it used ML on my Swampert, I used earthquake, and Jynx didn't die, even with that horid defense. It was faster than me of course, so it used lovely kiss next turn, I fell asleep. Then, it used perish song, I didn't wake up. By the third turn or W/E, I was STILL sleeping, and well, I ended up fainting because of perish song. And Swamppy was my last, pokemon, too...
~When I was battling Tucker in the Battle Dome for the gold symbol, his Swampert froze my Gyarados, and he never defrosted. So I died eventually, and had no choice but to send out Kingdra. I used surf, since that was the best move I had, he used mirror coat, I died, lost. Now if only I hadn't gotten frozen, then I probably would've been able to win.
I've been haxed much more than this, but typing all it up would take another few hours probably...