This is the saddest day of my young life, Batman.
5 seconds sound clip from Batman (1966) - The Yegg Foes in Gotham (S2E14) TV Series.
You can hear this line at 00:08:17 in the Blu-ray version of the movie.
Quote context
[...]
- You are through. Finished. Fired. Up. Out. Out. Over. Up. Out.
- We're witnessing a new low in community relations, Robin.
- And as for you, my caped incompetents, I hereby egg-xpell you from the Gotham City limits.
- If you so much as show your masks around here again, I'll have you both egg-xecuted.
- This is the saddest day of my young life, Batman.
- Goodbye, Gotham City. You were my kind of town.
- If Batman and Robin ever come back to Gotham City they'll be shot on sight. Ain't that great?
- Hold your egg-xuberance, Foo. My amazing brain tells me that we haven't seen the last of them yet.
[...]