Actually, my favorite comparison to other holidays is this one about Chanukah.
The central story of Chanukah--the oil lasting eight days, yadda yadda yadda--is not only a lie, but an obvious one: it is nowhere mentioned in either of the two Books of Maccabees, which provide the central textual source for the Chanukah story. It's just made up. And by the way--where are those Books of Maccabees, anyway? Roman Catholics have included them in their Bible, and some Protestants usually append the Apocrypha (where they are found) to the back of their Bible, but Jews leave it out. It's almost as if we're embarrassed by it.