I wish I could put something detailed here, with stats, levels, abilities, and all that. But, I can't, because the last time I had these teams together was years ago, when I had Pearl. So all I can put here are the Pokemon themselves. I'm also sort of lazy.
This is my first team. It has balance, can barely cover any weaknesses, and a Rock/Ground type with both types of attacks could destroy most of them. However, I seem to be best with this team, as bad as it is. For the most part, my trump cards are Shedinja, who can only be hurt by 5 types, and has been very helpful in a lot of situations. Nidoqueen, if I remember correctly, had Earthquake, Surf, and Thunder. Surf and Thunder both came in handy handling two of her Weaknesses. Crobat can handle Fighting types easily, which is a weakness shared by Tyranitar and Weavile.
Vaporeon is my real hit taker. She has good HP and decent Defenses.
Probably not the best choice of pokemon I could pick, but dammit, I know how to use them.
This is my more balanced team. They share very few weaknesses among them, and can cover the weaknesses of each other easily. Zapdos, being a Legendary, and Metagross, being a Pseudo-Legendary, are both fairly powerful. The most dangerous type for this team is Ground, which can be a pain for Houndoom, Metagross, and Lucario, but Quagsire can cover that easily. This team also has pokemon who can cover their own weaknesses, to a point. Quagsire is immune to Electric attacks, and Water, due to its ability. Metagross can take Dark, Ghost, and Fighting attacks, because of its types. Lucario can take Flying and Psychic damage. Gengar is immune to Ground attacks, and Houndoom is immune to Fire, due to Levitate and Flash Fire, respectively. I remember that I used Gengar to inflict Toxic poison, with Toxic or Sludge Bomb, and Confusion via Confuse Ray. For some reason though, I'm not as good with this team, I guess lack of experience with these pokemon compared to team 1.