My favourite (sarcasm) was my history final...
8 long answer questions (out of 10 given) to be answered, where our study guide had 25 (ie that any of the 25 would be on the exam).
As well we had to do 2 essays out of 3 given on the exam, of which 8 in total was on our study guide...
So yeah, it was a major know everything, and we had 3 hours to complete it.
What's sad is that we had the exact same format for our midterm, and that was only 1.5 hours, only difference was 5 long answer questions instead of 8.