The only ones I remember are the odd-ball memorable ones, like the time a girl came in her senior prom dress. Remember, this was the mid-80s so just imagine the dress!

Seeing all these "Is this dress ok for Pref?" threads, I'm thinking if you have to ask it probably isn't.

I'll also add:

If you can go straight from Pref out to the club without changing (unless it's a 1950s supper club) it probably isn't.

I've been to at least 15 or 20 prefs as a collegian and then an alum helping out, and I only remember two outfits - one because the girl had on such a great outfit and had accessorized perfectly, and one because the girl looked completely wacky. Otherwise, it's sort of a whirl of cocktail dresses and sheaths.