E-4 Team Types (Excluding the Champ)
FIGHT, PSYCHIC, FIRE, DARK/GHOST
Counters(That I can think of):
Flying, Dark, Ghost, Normal, Water, Ground, Rock.
The entire party should be around Levels 57-62
You will also need APX 25 Full Restores, 50 Full Heals (or Castelia Ice), 60 Max Potions, and 10 revives.
*It also wouldn't hurt to have Pokemon in your party hold stat-affecting hold items; I.E. Water Type = Mystic Water, Dark Type = Blackglasses, Quick Claw, Scope Lens, Focus Sash.
Also a great tactic to use is to have a Pokemon with the move endeavor and have it hold a focus sash.
Here's how it works
Opponent's Speed > Your Speed
Turn 1: Attack that would otherwise KO your Pokemon
-Focus Sash activates-
*You use Endeavor
Opponent's HP = Yours = 1HP
Turn 2: Use MAX Potion
Opponent attacks again leaving you with 1HP
You then follow up with any other attack besides Endeavor and KO the opponent!
For leveling up your Pokemon fast, trade your Pokemon to another game (White or Black) and do Extralink missions till you can use the EXP+++ power, then trade the Pokemon you wish to level-up and let it hold a lucky egg while activating the EXP+++ power.
NOT O.T. = EXP BOOST
Lucky Egg = EXP BOOST x2
EXP+++ = EXP BOOST x5