Boredom= thread time.

Tier: RU

Notable moves:
Bug Buzz / Giga Drain / Air Slash / U-turn / HP Fire
Other Moves:
HP Fighting / Psychic / Shadow Ball / Protect

Tinted Lens: "Not very effective" moves have their power doubled.
Speed Boost: Speed increases one stage each turn

With two of the most threatening abilities in the game, its no wonder that Yanmega is ripping RU to shreds. With tinted lens, Yanmega spams Bug Buzz in the faces of opponents who watch their resists go to waste. With choice specs, Yanmega can 2HKO the majority of the metagame. Tinted Bug & fighting coverage gives perfect neutral coverage, so Yanmega's two other moveslots are usually occupied by U-turn for fleeing from special walls, and a filler.

Alternately, Speed Boost boost is like a better scarf without the drawback. After one turn setup with protect or detect, Yanmega outruns almost the entire meta. Otherwise fast Pokemon with rock moves can wipe the floor with him.

Choice Specs
Yanmega@ Choice Specs
Tinted Lens
EVs: 4 HP / 252 Spe Atk / 252 Spe
Modest (+Spe, -Atk)
-Bug Buzz
-Air Slash
-Hidden Power Fire
-Giga Drain / U-turn

A few sets:
Speed Boost-
Yanmega@ Life Orb
Speed Boost
Modest Nature (+Spe, -Atk)
EVs: 160 HP / 252 SpA / 92 Spe
- Protect
- Bug Buzz
- Air Slash
- Giga Drain / HP Fire