Toph and Katara (Avatar: The Last Airbender): Toph was always seen as the tomboy type that loved to fight while Katara was the girly type, who developed into one of the best fighters in the show.
I kind of liked the clashing of the two personalities even though they were on the same team. They both represented the spirit of where they came from. Toph's rugged attitude from the Earth Kingdom while Katara's gentle flowing nature came from the Water Tribe. The idea first arose during "The Chase" and touched upon again in "Tales of Ba Sing Se". They finally came to blows in "The Runaway".
An object at rest cannot be stopped.