I thought the "keep" in Keep on the Borderlands was a verb. I always assumed that the higher-level modules were for when you left the borderlands and met the really scary stuff. In addition to committing almost all of the immature monty haul offences already described earlier in the thread involving gods, magic items and other icky stuff, I once, as a kid designed a procedure for characters creating planes of existence and then ruling them. I guess it's no surprise I'm not doing my MA on Mormonism.
When I was 11, I published my homage to the Isle of Dread in my school newspaper. It was edited for length my the teacher running the paper and many of the apparently meaningless series of random letters and numbers in parentheses were removed or edited-down so that it would be a better read.
I guess my most embarassing confession is that, to this day, when I suffer from insomnia, I lie in bed and create characters until I fall asleep and then throw out their sheets (yes -- I mean the sheets on which the characters are described; I'm not that weird) in the morning.