> Can you remember one time in history where we now like "thanks god they censor these thoughts!"?

Well, the honest answer to the "can you remember" question is going to be misleading. By the nature of the thing we're talking about, the historical things like that are things that people aren't going to remember.

If you believe in "to the victor go the spoils" on the information front, then successful censorship (and more generally propaganda) is always on the right side of history.