Legal Question in Business Law in Massachusetts

For ease of use, the LLC will usually make the most sense. The company hiring you may sometimes have a say in it as well. For example, in the realm of entertainment often they only want to contract with incorporated entities as they believe it provides more insultation for them. The LLC also allows for check the box tax status so you can always change the way the entity is treated if it was preferrable to tax as a corp or even an S-corp later. It's a tax question, so you may want to consult your CPA.