In my most recent exam I had one of my "name the surface this equation decribes" questions. Predictable as the sun rising, so easy to study for, yet resulting in delightful answers all the time. The following answers were all supposed to be "elliptical paraboloid":
cone shaped (warped)
eclipse
epilleptical sphere
trechter [Dutch for "funnel"]

Always good for the mood.

-Tracy, unsurprisingly