Athenodoros
Official Smogon Know-It-All
Not sure about you, but I almost always had Gar, and he was amazing. So many teams aren't prepared for it after losing one counter, and they can just be swept. Definitely one of the better OUs.I'm gonna say Gengar and Flygon, because people actually thought those things were good
When I was using SubSplit Gengar because people told me OMG it can beat Blissey!!! I tried it, but Blissey would always break my sub, and I'd have to predict if it would attempt to paralyze me or attack me. Not to mention whenever I got Blissey under 40% Focus Blast would miss. Same goes for the scarf set when Focus Blast would miss.
EDIT: I run Sub + 3 attacks. It doesn't really have any problems with Scizor, and Tyranitar is disposed of 91% of the time.