With Weebly you can make a nice looking wedding site, for free.
While they don't have the custom wedding features (special smartphone apps for guests, seat planner, custom wedding designs, etc), you can make a site like this one quite easily
With Weebly you get the stability of one of the biggest names in the Website Builder space, so the site will be stable and the interface is very friendly.
There's only one wedding theme on the site, which should give you the bare-bones of your future wedding site.
