The simple answer is any theme that suits your website goals.
However we recommend selecting a theme that does not have real estate specific functionality as the Easy Property Listings plugin for WordPress will take care of that and can sometimes conflict.
All themes can work with Easy Property Listings and work better once the theme setup is completed.
The more complicated answer depends on your end goals, your experience and how serious you are for success with your real estate website online.
For me its like purchasing a branded computer back in the old days where they pre-load it with bloat ware and software that you never use and you end up spending hours uninstalling programs that slow down your computer.
Well the same goes for WordPress themes.