I think my team might not be the best team in the game, but they got me through the whole game from the first badge up to where I am now, at the Apophyll Academy.
This is my team:
Exploud - Level 40 - Soundproof - Crunch, Echoed Voice, Stomp, Bite
Emboar - Level 42 - Reckless - Rock Smash, Flame Charge, Ember, Heat Crash (waiting for some more powerful Fire-type moves)
Pachirisu - Level 38 - Pickup - Spark, Charge Beam, Electro Ball, Swift
Pidgeot - Level 41 - Keen Eye - Tackle, Wing Attack, Gust, Quick Attack
Kricketune - Level 40 - Technician - Slash, Cut, X-Scissor, Fury Cutter
Seaking - Level 42 - Lightingrod - Water Plush, Water Sport, Waterfall (learned on its own by leveling up, not by using the machine. I don't even have the machine for it), Horn Attack
As you can see, I focus on attacks that does damage, I don't usually use moves that restores your health, lowering your opponents stats, raising your own stats, etc.