There's one I've use a variation on few times. The original was:

"I hadn't planned on telling Sam an alien was doing his daughter." wink

[Originally from Unanswered Prayers in which a married Lois and Clark are contemplating telling Sam about Clark's Kryptonianness.]

I'm certain there are others I've reused either intentionally or not, but that's the only one that immediately comes to mind.

Carol