Here's my team after beating my rival, going through tons of routes and beating the 4th Gym Leader Maylene.
Grotle level 28
Tackle
Bite
Mega Drain
Razor Leaf
Staravia: King level 31
Tackle
Aerial Ace
Quick Attack
Wing Attack
Luxio level 27
Tackle
Bite
Spark
Thunder
Gabite: Cynthia level 27
Earthquake
Dragon Rage
Sandstorm
Take Down
Vaporeon: Napton level 23
Tackle
Blizzard
Sand-Attack
Quick Attack
Midnight: Houndoom level 25
Smog
Fire Blast
Bite
Payback
Grotle level 28
Tackle
Bite
Mega Drain
Razor Leaf
Staravia: King level 31
Tackle
Aerial Ace
Quick Attack
Wing Attack
Luxio level 27
Tackle
Bite
Spark
Thunder
Gabite: Cynthia level 27
Earthquake
Dragon Rage
Sandstorm
Take Down
Vaporeon: Napton level 23
Tackle
Blizzard
Sand-Attack
Quick Attack
Midnight: Houndoom level 25
Smog
Fire Blast
Bite
Payback