My friend Wes Dumey does a lot of work in the business intelligence sector as a contract employee and has a post worth reading called The Great Debate - Employee vs. Consulting. I don't agree with all of his points, but it's an interesting conversation to have. I do agree that too many of us seem overly focused on benefits, rather than just looking at the dollar value of the benefits and adjusting the wage accordingly. For example, I pay about $6k a year for health insurance for my family. It doesn't matter if I make $100k and get free insurance, or make $106k and pay my own, I net the same (assuming benefits are comparable/reasonable). The challenge is that employers have to put everyone in the insurance pool to get the rate, and so as an employee you can't negotiate for that extra $6k easily (and the same for the 401k match). But as a contractor, all doors are open - you just have to understand your own costs, financial goals, market value, and then ask!
I don't want to comment much until Wes does part 2, but I'll finish with this; most of us prefer to be employees for three reasons:
Wes has posted Part 2 before I get could this posted, so I'll wait on his Part 3 to finish my thoughts.