Free HTML Form Builder: pForm
pForm is a web-based & free HTML form builder application for creating good looking forms easily.
It offers various color schemes to get started & enables you to design your form with an Ajaxed interface.
Any type of form objects (text fields, checkboxes, dropdowns, file upload fields, etc.) can be added & every field can be customized (field label, type, size..).
Once the form design is completed, it can be previewed & ready-to-use HTML/CSS files can be downloaded as a .zip file.
To get amazing features like saving entries to database, input validation & much more, you can check the commercial product of the service: MachForm.