most laughably bad, skill-less, entirely unsuited to rapping rapper out there? And I don't mean stuff like Robbie Williams on Rudebox, I mean people that would actually put 'Rapper' as their occupation on their passport.
I vote Will.I.Am. Just absolute rubbish. "I met a girl, down at the disco, she said 'l-l-l-l-let's go'". I know noone would claim he IS a good rapper, not even his mum, but come on...
My vote for someone generally regarded as good who actually isn't goes to RZA. Makes up words to shoehorn rhymes in, mumbles and trips over his words, irritating tone to his voice. Stick to producing.