Vote for only Pure Flying Type Pokemon.
Thundurus is amazing once you get the hang of it.
It can use infinite Rain from Drizzle to its advantage by spamming STAB Thunder. It can set up with Nasty Plot or Agility due to Prankster, which also gives it priority Thunder Wave to cripple many fast sweepers in the game.
Although risky to use, it can use Focus Blast to deal with a handful of Steel, Dark, Ice, and Rock Types.
Dark Pulse is something against Ghost or Psychic Types if you feel the need to have that kind of move.