Well for this I would like to show my 3 favorite parties..ever.
Sunny Day Team
Ninetales(Heat Wave, Solarbeam, Dark Pulse, Hypnosis) Drought
Espeon(Psychic, Shadow Ball, Calm Mind, Morning Sun) Magic Bounce
Venusaur(Solarbeam, Sludge Bomb, Sleep Powder, Synthesis) Chlorophyll
Umbreon(Moonlight, Payback, Yawn & Protect) Synchronize
Togekiss(Aura Sphere, Air Slash, Thunder Wave, Roost) Serene Grace
Cresselia(Thunder Wave, Reflect, Light Screen, Moonlight) Levitate
Strength Team (UBER)
Zapdos (Tailwind, Roost, Heat Wave, Volt Switch) Lightningrod
Reshiram (Blue Flare, Anicentpower, Extrasensory, Draco Meteor) Turboblaze
Lugia (Aeroblast, Psychic, Roost, Calm Mind) Multiscale
Latias (Psychic, Dragon Pulse, Calm Mind & Recover) Levitate
Mewtwo (Psystrike, Aura Sphere, Calm Mind & Recover) Unnerve
Darkrai (Dark Void, Dark Pulse, Dream Eater & Nasty Plot) Bad Dreams
Strategic Team
Skarmory (Spikes, Stealth Rock, Whirlwind, Roost) Sturdy
Porygon-Z (Hyper Beam, Psychic, Tri Attack, Pain Split) Adaptability
Hydreigon (Dragon Pulse, Dark Pulse, Tri Attack, Fire Blast) Levitate
Metagross (Meteor Mash, Earthquake, Bullet Punch, Hammer Arm) Clear Body
Lucario (Aura Sphere, Dark Pulse, Vacuum Wave, Nasty Plot) Inner Focus
Blaizken (Protect, Sky Uppercut, Fire Blitz & Shadow Claw) Speed Boost