To get the ball rolling, my five suggestions are...
- Keith Lemon (I guess this is a character, not a person, but oh well)
- Hunter Moore (revenge porn mogul, general scourge of humanity)
- Katie Hopkins (do I need to clarify)
- Nash Grier (not the worst Viner I suppose but the most recognisable for being crap, plus has questionable behaviour)
- Jaden Smith (self-important little twerp)
I'm sure someone else will come up with Helen Wood