When Rose is held hostage by a Dalek (Tor), Nine wants to kill his future Dalek-self rather than spare her life — but finally chooses to rather save her. Cue Ten smiling with tears in his eyes. Even better, it's ONE that calls him out. To be fair though, the idea was that Ten's regeneration would eliminate the Dalek programming.
When Four is falling to Earth and believes it to be the end of his life, he finds that he can at least take solace in fact his place of death is his beloved planet Earth.