a. Sole proprietorship
i. Positive – simplifies decisions and allocation of responsibilities
ii. Negative – personal liability
b. General partnership
i. Positive – no local or state filings are necessary to create
ii. Negative – personal liability
c. Limited Liability Partnership
i. Positive – limited personal liability
ii. Negative – limited partner can’t make management decisions
d. Corporation
i. Positive – limits personal liability
ii. Negative – must adhere to corporate business practices

Also, all forms have to register with CAB, so all, by definition, have a state registration requirement.