What are the characters that has their own unique abilities throughout the DB series?
I would also add:


General Blue - psychic abilities
Giran - Merry-Go-Round Gum (although it's stated that members of his race can use it)
Man-Wolf - turns into human during fullmoon 


There are also other characters like Chiaotzu who can use telekinesis, but I'm sure there were some other characters that could do that as well.