The Cambridge Advanced Learner's Dictionary is not very well-known at Bavarian schools - but (of course) it's a very good dictionary all the same.
The publishers offer a list of the Top 50 words that were looked up in 2002, 2003 and 2004.
Would you have had to look them up, too? - Take my advice, and take a discreet look ;-)
Top 50 in 2004/looked up at the online version of CAL