If you want it by movie:
SW: Battle of Yavin, when the music stops and they get to the death start corridor. Most specifically, when Vader says "close up formation" and we see the ships passing by.
ESB: see above.
ROTJ: Luke atacking Vader after he talks about his sister.
And of course, why should we forget about the prequels.
TPM, AOTC: the closing credits. Wheew, that's over...
ROTS: laste minute before the closing credits. Aaaand... the credits.