Which free website builders do you use and why?

This has been discussed before on Classroom 2.0 but I'd like to get a feel for the state of the art. After all I have changed wiki providers several times over the years as things have evolved so I'd like to know how things currently stand for website builders.

A Google search for 'free website' turns up the top 5 results:

webs

weebly

wix

jimdo

and yola

in that order.

I'm most interested in student creation so I want to know which you have your students use, rather than what you use yourself.

Why do you use the one you use?

Have you changed what you use? Why?

Only weebly has an education specific version as far as I can tell with a cursory glance, would that or does that influence your decision to use it?

Cheers,