I do agree about RV, we are also using it, but I am not a fan of such SiteBuilders as a whole to be honest. I can see why novice users find them so easy to operate but they are just so limited - limited in design, limited in functionality, limited in extras. And I bet that anyone with the right mindset can sit down and learn a CMS like WordPress in no time and get much more freedom.
But enough about my midnight ramblings...back ontopic, apart from RV I've heard various people that fancy Wix, Weebly, Zyro and Trendy Builder. Can't really vouch for any of the options as I've personally used only Wix from those, but they seem pretty straightforward and easy enough for the end user.