Whats is the best free website builder?
Depends if you have experience with HTML scripting or not. Coffeecup Software offers an easy website builder called Visual Site Designer. You do not need any HTML experience as the site is developed visually without code. Just position your objects into place and the software will program the HTML code for you.
If you are looking for a code editor try the Free Editor which includes wizards and tools to make it easy to develop your website.