Here are some fun ones, if anybody is feeling up to the task:
Leechwalker (MMII): Have you ever been walking down the street and though, "Man, I wish I was a giant mass of writhing leeches?" Well worry no more with this class! I think that turning something with 2 real abilities into 10 levels would be tough, and scaling a con drain properly as well.
Drowned (MMIII): This one is pretty cool. A drowning aura? Kill people in 3 rounds? Pretty sweet. Majora's Mask BEN, anyone?