What are good Pokemon teams in Hoenn region?

Answer 1

Mine are:

Blaziken (fire, fighting), Flamethrower, Sky Uppercut, Bulk Up, Aerial Ace

Gardevoir (psychic), Psychic, Calm Mind, Shock Wave, Reflect

Flygon (ground, dragon), Earthquake, Crunch, Double-Edge, Dragonbreath

Breloom (grass, fighting), Headbutt, Giga Drain, Mach Punch, Sky Uppercut

Wailord (water), Amnesia, Ice Beam, Strength, Water Spout

and Lanturn (electric, water), Surf, Thunderbolt, Confuse Ray, Attract.

But other good Pokemon to mix-and-match are:

Milotic (with Attract and Surf),

Altaria (with Dragon Dance),

Ninjask (with Swords Dance and Baton Pass),

Shedinja (with Shadow Ball),

Armaldo (with Battle Armor and Bulk Up TM),

Swellow (with Endeavor, Facade, Aerial Ace & Quick Attack),

Camerupt (with Eruption),

Absol (with Swords Dance),

Whiscash (with Earthquake, which it learns naturally by leveling up),

and Slaking, if you can get past Truant (with Focus Punch, Yawn, or Slack Off).

And in using older Pokemon originally from other regions:

Dodrio,

Houndoom,

Ursaring,

Donphan,

Starmie,

Electrode,

Jolteon or Espeon (evolve from Eevee),

Miltank,

or Alakazam or Machamp (use a Gamecube game to trade-evolve it if you can, like Pokemon Colosseum or XD).

For starters:

Torchic is always the best. Whiscash and Quagsire make Mudkip obsolete and Treecko is horrible when it evolves. One of the weakest of any generation, Sceptile only has speed going for it and nothing else. It's as bad as Thyphlosion or Meganinum.