It depends on who you ask. If you ask a lawyer they will tell you to create an LLC for every property you own. If you ask an insurance agent they will tell you to buy insurance out the wazoo.
I think the asset protection mantra pushed on landlords is solely designed to make money for lawyers, insurance agents and asset protection gurus. In 20 years as a landlord I have yet to need asset protection. It doesn't mean I don't have it. Just saying I haven't needed it.
Here's the problems I have with LLC madness and why I prefer liability insurance.
1. I've heard from several lawyers that they haven't met an LLC that they couldn't pierce.
2. LLCs only offer upstream protection. Meaning protection from tenants. If you personally get sued for something outside your businesses they can still come after your LLC ownership interests and your assets.
3. When your LLC does get sued who is going to represent you? You will have to pay for a lawyer. As opposed to insurance in which it is the insurance company that pays its lawyers to settle or defend you. If you have ever gotten involved in a lawsuit before you will realize that the costs can mount quickly. Then when you lose, you are not only out the single property in that LLC but tens of thousands in legal fees.
4. Bookkeeping and incorporation costs are a pain.