It depends on case, if you want to use free hosting and subdomain that are provided by each platform, or if you will install the application on your own hosting and use own domain.
WordPress is probably the most popular website building platform. According to information on wordpress.com
, currently 37% of the web is built on their platform. It is user friendly and it has many features, plugins, themes and quite large range of modification possibilities. If you plan to use your own hosting and domain, I would recommend to install WordPress blogging platform.
If you plan to use free hosting and free subdomain provided by blogging platform, I would recommend Weebly.com
, because the WordPress is sometimes showing too many ads. Weebly is user friendly and allows you to use drag-and-drop website builder.