Rental property, which I had owned since I was 24 and thought was the ticket to an early retirement, I am now declaring to no longer be a valid investment. The reason is simple:
Americans are no longer reliable enough to rent out something valuable like property to them, let alone are worth the legal risk. You throw in the general deterioration of your pool of renters as well as the market being flooded with people who bought more house than they could afford, not to mention every local government now jacking up your taxes to pay for their pet green projects, and it isn't worth it any more.
Instead, I suggest buying storage properties.
You see, physical items cannot sue. They cannot complain that there's mold in the basement, or when you paint with Killz to kill said mold, it smells chemically. Physical items do not cause damage, do not freeze nor burst in winter, and for the most part are easier to deal with than live humans that rent from you.
So take the Captain's advice. No more rental property.