Hercule and Vegeta in “Unfinished Business”

[about Majin Buu] He fought that Evil Buu with all he had.

Vegeta

Oh, right! And what if he's not all gone!? What if he blows his stack again and produces another killing machine!? What then!?

Well, I don't know.

Vegeta

Well, I do! It would mean the end of the world! You might be willing to take that gamble! But I'm not!