Yeah, the classic grease-paint and doggy balloon clowns are annoying and creepy as hell. One of my earliest memories is of being followed around by one at a fairground, barking 'DON'T DRINK YER BATHWATER!' and scaring the crap out of me...that was the first time I ever flipped anyone off to their face. I was six.
Cirque Du Soleil clowns, and classy ones, are cool though. I love them.