My dream team consists of my favorites, a couple that I would otherwise not use competitively.
1 --- Pikachu
2 --- Dragonite
3 --- Gyarados
4 --- Mew
5 --- Bronzong
6 --- Leafeon
Other Pokemon that I often rotate out of this team are:
Starmie, Garchomp, Mewtwo, Jolteon, Charizard, Zapdos, Salamence, Diagla, Tyranitar, and Giratina. I do not have a Mew yet....but he's still in my dream team. I also don't have a Salamence yet...however everyone else I do have. Every Gen is 1, 2, 3, and 4. 5th Gen however is a little different:
1 --- Victini
2 --- Zekrom
3 --- Serperior
4 --- Volcarona
5 --- Archeops (Hope that's spelled right)
6 --- Hydreigon