Pokémon Ruby and Sapphire/The Elite Four

These guys are the last bosses. After defeating them, you face the champion. (In Red, Blue, Yellow, Fire Red, and Leaf Green, this is your rival, who I will refer to as Gary. Gold, Silver, and Crystal have Lance as the champion. In Ruby and Sapphire, you fight Steven. You battle Wallace in Emerald.) The Elite Four from Ruby and Sapphire will be covered here.

He has an, a , a , a , and a. The Shiftry knows Extrasensory, so beware!
 * The first of the elite four is Sidney. He specializes in dark Pokémon.

Fighting or Bug Type will do well against all of the Dark Types. and are fine choices as well. Also, if playing Ruby, the legendary is nice. Its fire moves will work well against Cacturne and Shiftry. Ground moves (Earthquake, especially) can knock out Sharpedo.

She has a, two , and two. Dusclops knows Ice Ball, so keep far away from it. Earthquake attacks work on this team. Ghost or Dark Types that you have will win.
 * After Sidney comes Phoebe, a user of Ghost Pokémon.

She has two, two , and a. Make sure you have a strong, because Walrein can use Sheer cold! The best you can do is bring some hefty Electric Types. Leave your Fire Types.
 * Next up is Glacia, with Ice Pokémon.

He has an, , two , and a ! If you have a good Ice Type, it will beat this crew!
 * Drake, the Dragon Master, is the final of the four.

Beware the, , , , and ! Get Fire Pokémon! Face Skarmory with Fire Pokémon, Aggron with Ground Pokémon and everyone else with Water Pokémon.
 * The champion, Steven Stone, has mostly Steel Type Pokémon.