I'd even go so far as to say that Spiegelei means sunny side up exclusively. Dunno what to call the other variants though, maybe just "gebratenes Ei" or something.

When I went to that American diner with the guys in San Diego, I was totally confused when the waiter asked me how I wanted my eggs. cpratt had to explain to me that there are different styles. He listed them all, but I couldn't make any sense of them at the time. :D