Ok, I've never actually done cold calling. I don't like being on the receiving end of cold calls - so I figure others wouldn't like it either. But in person would be much better.
People usually do not like it, that's what makes it hard work. It's also more effective because it allows collecting more intelligence. The decision maker's personal assistant knows something about the company and can provide valuable insight to the organization and its pain points. The receptionist knows the org chart.