During the last few weeks I have been using a WordPress theme called Massive Dynamic. You can find a demo here, or better, all the demos available with this powerful tool.

It has over 60 pre-built websites, and after installation it lets you load one of the available configurations. In the documentation you can find all the information you need to know so no need to repeat them here.

After using it I must say that, compared to other themes, you really need to be prepared to spend quite some time to get used to online editing (which replaces partly the use of the WordPress backend admin).
You also need a fast pc and internet connection. I experienced many times a frozen browser.

This said, the final website are really modern, of course responsive and also quick to load.