Here's a couple sets, one for Mega Lucario, and one for non Mega for OU.
Fists of Fury (Lucario) @ Weakness Policy
Ability: Steadfast
Level: 50
EVs: 156 Atk / 116 SpA / 236 Spe
Naive Nature (+Spe, - Sp Def)
- Close Combat
- Flash Cannon
- Water Pulse
- Endure
Close Combat + Flash Cannon for Dual Stab, and Water Pulse for coverage as Lucario doesn't like Fire or Ground types. Speed ends up at 154, which outspeeds pretty much every base 101 or less with a neutral nature, or base 89 or less with a beneficial nature.
Fists of Fury (Lucario-Mega) (M) @ Lucarionite
Ability: Adaptability
Level: 50
Shiny: Yes
EVs: 4 HP / 116 Atk / 4 Def / 132 SpA / 252 Spe
Naive Nature
- Close Combat
- Flash Cannon
- Water Pulse
- Bullet Punch
Steadfast or Justified before Mega Evolution. Your choice.
The idea here is 180/177 attack stats at neutral stat modifications at level 50, post mega evolving. Adaptability ability, so three stab attacks, to benefit from it. Water Pulse for coverage, as most ground types have poor Special Defence, and/or are x2-x4 weak to water.
Here's a set I like for Salamence, Mega and normal.
Menace (Salamence-Mega) @ Salamencite
Ability: Aerilate
Level: 50
EVs: 100 Atk / 156 SpA / 252 Spe
Naive Nature
- Outrage
- Fire Blast
- Hydro Pump
- Return
Dual Stab, just make sure you faint their Fairy Types, before Outrage. Outrage over Draco for reliable damage, and no stat drops + Stab. Return for Stab #2. Fire Blast For Scizor + Ferrothorn. Hydro Pump for the myriad Ground/Rock types, mainly Arceus-Ground, Non Primal Groudon (it's a 2hko on Groudon, in the sun, if it's an offensive Ev Groudon).
Destroyer (Salamence) (F) @ Flyinium Z
Ability: Moxie
Shiny: Yes
EVs: 4 Atk / 252 SpA / 252 Spe
Mild Nature
- Outrage
- Fire Blast
- Hydro Pump
- Fly/Aerial Ace
This set relies on a Moxie boost, given very little attack evs. Outrage > Draco as this set actually relies on special attacks. Fire Blast for the usual x4 weak Pokemon. Hydro Pump for mainly Gliscor, Rhyperior, Golem, and Heatran. You could swap Fly for Equake, but I like the flying type stab, to deal with Bug/Fighting/Grass types.