Pokemon for User Challenge?

Hey guys! I recently found my old Pokémon emerald cartridge and wanted to begin playing again. However, I wanted to do something that challenged me. So, I am going to do a user challenge. Basically, for those who don't know, a user challenge is when users such as yourselves, suggest Pokémon or me to use in my game. So for example, "FakeUser0842 says: Use a Magikarp." I will be required to use whatever Pokémon the users tell me to. I have some rules though.

1. Any Pokemon will be fully evolved, if you say "Ralts" I will evolve it to Gardevoir.

2. No post-game Pokemon, I need to be able to have a party of 6 by the elite four.

3. No trade-evolution Pokemon as I won't have access to another R/S/E user.

Other than that, you guys can suggest away!