Probably depends on your situation. You won't get any " more" liability protection using one over the other, if that is the question. Either the LLC holds up in court as a legitimate business, thereby shielding your personal assets and those of your wife, or it doesn't.
Filing taxes does get more complicated with a multi-member LLC b/c then you have to file a separate return and send out K-1 forms to each member by such and such a date. Single member LLCs can just file a Schedule C with your personal taxes and then an " informational tax return" with the fed and state. It is somewhat easier to do.
A good rule of thumb is SIMPLE IS BETTER. Given two choices with equal outcomes, choose the simpler one.
Also, before you leap on the LLC wagon, it may be worth your time to research putting the properties instead into a trust. Should one of you die, and the assets are held in an LLC, you can get clubbed with the estate tax and/or the value of the home will count towards your $2million cap. People do die and using a trust can provide both the liability protection you are seeking, and some specific estate tax benefits as well. Added bonus.
-Jeff