lelouch and suzaku from code geass, even if theire friendship had been ruined in the end they still help each other (suzaku still consider lelouch as a friend even if it's just in the end) "dying is the only way for us to repent our sins" though i dont agree in theyre own belief
In a way, Joey and Yugi have been there for each other, as well as Yugi and Atem. Then again, Joey, Tea, Tristan, Yugi and Atem have all been there for each other.