The top ranking decks in the Pokémon world are constantly changing, but there are a few Pokemon decks that will always be powerful.
Top Pokemon Decks
This deck uses lots of energy to hit things hard. It rarely makes use of Yveltal-EX‘s Y Cyclone but relies mainly on Evil Ball. Darkrai-EX can keep things moving fast with its Dark Cloak ability. The Dark Explorers Sableye can get back your Dark Patch and Hypnotoxic Laser.
This deck needs Stage 2s to win. Miltank is the main attacker, and Empoleon gets you set up. Dusknoir is really just always good to have, but the nicest thing is not having to run so much energy. You really only need 6 to 10 water energy. Muscle Band is a nice addition, because Miltank only does 80. If you actually run out of energy, Super Rod is here to help. With some other trainers to help, you can easily (and quickly) win the game.
This is arguably the fastest deck there is. Vespiquen can do Bee Revenge for 20+ 10 damage for each Pokémon in your discard pile. It only needs 2 Colorless energy to attack. Unown can directly put itself in the discard pile, and Flareon will help trigger more weaknesses.
This deck is probably one of the most annoying decks to play against. Seismitoad-EX completely blocks you from playing item cards, while the Crobat evolution hits from the bench. When played right, this deck is nearly unstoppable.
This deck is plain mean. It sits there, waiting to get beat, and then when you almost knock out the Wailord-EX, it gets scooped up. Plain mean.