I just do a simple color change or one of the tivo effects...And like visualartist said just about everything is crazy in regular peoples eyes. You could do the simplest effect and get great reactions.
Whenever someone asks me to do something "crazy" I usually perform a levitation effect. Either that or a really nice color change. Such as Cardini (or its variations) or Clipshift.
Wow, that was the top three tricks I was going to name.
It doesn't mater what trick you perform because they aren't familiar with the "craziness" of tricks, as long as you give a solid performance than the trick should impress them.