I forgot about Future Trunks and Future Gohan. They are definitely very good people. The rest of the cast is fairly neutral. They have the power to help people and change the world, but none of them ever do anything for non selfish reasons except Krillin and 17. They'll help you if they see you about to get hurt or something, but they won't go out of their way.

For Vegeta, I don't think original Vegeta even considered Earth worth ruling. He was too prideful to want to rule a race of pathetic weaklings.