Sceptile @ Leftovers
HP Fire
Dragon Claw
Leaf Blade
Earthquake
Take out Salamence due to higher speed, and destroy Skarm due to speed advantage AND since HP Fire is special, Skarm's weakness.
Gardevoir @ Leftovers
Psychic
Calm Mind
Thunderbolt
HP Ice/Light Screen/Reflect
This set owns hard. Psychic takes out Fighters or Ghosts. Calm Mind for turns when it's safe to power up. Thunderbolt for bulky waters other than Swampert. HP Ice is the preferred move for Mence and Flygon, but the other two work if you want utility.
Machamp @ Leftovers or Choice Band (no Bulk Up/Sub/Rest/Sleep Talk if using CB0
Cross Chop
HP Ghost
Sleep Talk/Ice Punch/Bulk Up/Sub
Rest/Dynamicpunch/Focus Punch
This thing is by far the best fighter in Emerald. Ice Punch to destroy Salamence, who can't do much other than HP Flying. Sleep Talking Machamp is awesome, but not entirely necessary. Bulk up to ensure OHKO on Blissey or other Pokes like Skarmory with Cross Chop. HP Ghost to nail Ghosts hard. Subpunch is just an idea.
Medicam @ Choice Band
Fake out/Brick Break
Focus Punch/Hi Jump Kick
Shadow Ball
Rock Slide
Just ownage. Use it.
Tyranitar @ Leftovers
Dragon Dance
Earthquake
Rock Slide
Substitute
Look at my sig.
Salamence @ Choice Band
HP Flying
Rock Slide
EQ
Dragon Claw
Hi, I'm CBSalamence. I owned everyone and everything in Gen 3.