Scizor

[SET] - Recommended
name: Bulky Swords Dance
move 1: Swords Dance
move 2: Bullet Punch
move 3: Bug Bite / Superpower
move 4: Roost
item: Leftovers / Life Orb
nature: Adamant
ability: Technician
evs: 252 HP / 40 Atk / 216 SpD

[SET]
name: Choice Band
move 1: U-turn
move 2: Bullet Punch
move 3: Superpower
move 4: Pursuit / Quick Attack
item: Choice Band
nature: Adamant
ability: Technician
evs: 248 HP / 252 Atk / 8 Spe

[SET]
name: Offensive Swords Dance
move 1: Swords Dance
move 2: Bullet Punch
move 3: Superpower / Brick Break
move 4: Bug Bite
item: Life Orb
nature: Adamant / Jolly
ability: Technician
evs: 252 Atk / 4 SpD / 252 Spe

[Other Options]

There are few viable alternative sets to those listed above. A Choice Scarf set can be quite an effective scout, hurting foes with a quick and powerful U-turn while being an effective revenge killer, much like Choice Band Scizor. Also, a Roost set with Life Orb + 3 attacks is viable, granting Scizor durability and coverage, in exchange for losing the wall-shattering power that would be offered by Swords Dance. Scizor can also run an effective Baton Pass set with Agility or Swords Dance, but on the whole this is outclassed by Gorebyss or Huntail passing Shell Smash. Finally, Iron Head is a stronger move to use for Scizor's Steel-type STAB, but it is largely outclassed by Bullet Punch, though it would be the STAB move of choice when trying to abuse Choice Scarf.