I like his speech to the rental car clerk as well.
Belushi’s speech in Animal House is pretty great as well.
In Patton I prefer his speech about the Carthaginians and his ‘apology speech’ to the opening speech.
I also like his little pep talk during the race to Bastogne. “…And if we are not victorious, let no one come back alive!” George C. Scott was so great at eye-bulging fury.