OK, my three votes are: (Apart from the Nessy, I'd be shocked if anyone votes for that level, especially if this is a DOS contest)
Tricky 10: Challenges the player to work with two entrances with a high percentage requirement. Quite a tall order for an easy level which is actually a good thing.
Mayhem 13: Well planned 8-skill level, and has quite a few solutions too, fortunately they aren't too easy to see...
Taxing 8: It was a tough decision between this level and Taxing 10, as both these levels have great solutions that aren't easy to spot. I picked 8 because of the better artwork and title name, and that I found this one a bit more difficult than the other one.