I used DougJustDougs stats to find out the most common sets and most common Pokemon combinations.
Sets
Scizor (Choice Band) - 11.4%
Flygon (Choice Scarf) - 10.8%
Vaporeon (Wish Support) - 8.58%
Lucario (Swords Dance) - 8.45%
Azelf (Lead) - 8.37%
Gyarados (Offensive Dragon Dance) - 8.36%
Scizor (Swords Dance) - 8.28%
Heatran (Choice Scarf) - 8.25%
Gyarados (Bulky Dragon Dance) - 8.21%
Starmie (Life Orb) - 8.03%
Breloom (SubPunch) - 7.77%
Dragonite (Dragon Dance) - 7.18%
Swampert (Tank) - 7.15%
Rotom-A (Choice Scarf) - 6.68%
Rotom-A (Defensive) - 6.45%
Machamp (Attacking Lead) - 6.01%
Aerodactyl (Lead) - 5.84%
Skarmory (Physically Defensive) - 5.78%
Heatran (Stealth Rock) - 5.75%
Heatran (Substitute) - 5.56%
Tyranitar (Dragon Dance) - 5.42%
Tyranitar (Choice Scarf) - 5.16%
Metagross (Lead) - 5.03%
Blissey (Wish Support) - 4.86%
Starmie (Rapid Spin) - 4.38%
Gengar (Life Orb) - ~4.35%
Forretress (Physically Defensive) - 4.24%
Gengar (SubSplit) - 4.23%
Infernape (Special Mix) - 4.05%
Infernape (Physical Mix) - 3.98%
Suicune (Offensive Calm Mind) - 3.93%
Metagross (Agility) - 3.84%
Dragonite (Mixed Attacker) - 3.83%
Blissey (Cleric) - 3.76%
Magnezone (Steel Killer) - 3.68%
Electivire (Physical Attacker) - 3.65%
Gengar (Substitute + 3 Attacks) - 3.63%
Tentacruel (Support) - 3.58%
Heatran (Life Orb) - 3.51%
Empoleon (Agility SubPetaya) - 3.47%
Celebi (Physically Defensive) - 3.41%
Infernape (Lead) - 3.36%
Hippowdon (Physically Defensive) - 3.35%
Jirachi (Choice Scarf Lead) - 3.25%
Gliscor (Britscor) - 3.22%
Blissey (2 Attacks) - 3.21%
Gengar (Choice Scarf) - 3.13%
Shaymin (Special Attacker) - 3.09%
Jolteon (Choice Specs) - 2.92%
Kingdra (Substitute + Dragon Dance) - 2.82%
Snorlax (Curse) - 2.75%
Tyranitar (Choice Band) - 2.65%
Starmie (Choice Scarf) - 2.56%
Machamp (Substitute + 3 Attacks) - 2.52%
Zapdos (Special Attacker) - 2.51%
Togekiss (Paraflinch) - 2.46%
Dusknoir (Tank) - 2.43%
Zapdos (Physically Defensive) - 2.35%
Mamoswine (Physical Attacker) - 2.33%
Weavile (Physical Attacker) - 2.28%
Infernape (Nasty Plot) - 2.28%
Bronzong (Tank) - 2.22%
Dragonite (Attacking Lead) - 2.22%
Jirachi (Choice Scarf) - 2.18%
Forretress (Specially Defensive) - 2.16%
Roserade (Toxic Spikes Lead) - 2.13%
Zapdos (SubRoost) - 2.10%
Jolteon (Charge Beam) - 2.04%
Discuss.
Sets
Discuss.