Matt Cutts gives his 2 cents about linkbaiting
On a meta-level, I think of “linkbait” as something interesting enough to catch people’s attention, and that doesn’t have to be a bad thing. There are a lot of ways to do that, including putting in sweat-of-the-brow work to generate data or insights, or it can be as simple as being creative. You can also say something controversial to generate discussion (this last one gets tired if you overuse it, though).
I agree that the controversial thing can work really well, especially on blogs, but I also find that the "controversial" blogs that are always spouting out controversial comments 100% of the time tend to lose the controversy factor very quickly. It's like the boy who cried wolf. People get desensitized after a while if all they hear is attacks on other people or businesses.
Speaking of controversy, I think you should be cautious about posting slanderous comments on your blog, but if you name names when talking about controversial issues, you will get people's attention. A lot of people are closely monitoring the net for mentions of their name and they will swoop in to defend themselves if you mention them and if you're lucky, they'll link back to you from their blog and tell their readers how stupid you are.