To be honest I love Front Page but I'm not sure as to whether that is free or not.
I've always found it easy to work with, compared to dream weaver it is more basic, but if you want to do more complex things with your website then I'd recommend dream weaver. But for you, since you want an easy to use website builder to suggest to your clients, I recommend Front Page.
However as I said I can't tell you anything for sure regarding if it is free or not.
Good luck.