(This thread potentially contains spoilers for every Telltale game. Read at your own risk!)
It seems a lot of people have been using the Telltale Voice Extractor to find unused voice files in a lot of games. I don't have the extractor myself (stupid computer) thought it'd be nice if there was a thread where we could compile a list of every discovery people have found. Discoveries so far (the list will always be ordered chronologically by game)...
THE CITY THAT DARES NOT SLEEP: The Narrator making various music-themed lines, implying that early in development music (the record player in Max's brain?) would have played a large role in the episode. One line says that "the spirit of Sam and Max will never die," hinting that originally both of them would die.
POKER NIGHT AT THE INVENTORY: A dialogue between Max and Winslow about a murder occurring at The Inventory, hinting at a possible future sequel.
POKER NIGHT AT THE INVENTORY: Strong Bad saying various lines from the tutorial of Strong Bad's Cool Game for Attractive People tutorial, but with lines such as "Press the R1 button to..." or "Touch the screen to...", hinting at the possibility of porting SBCG4AP to the PS3 and iPad.
If you found something, share it!