Survicate - Collect feedback on your website and find out more about your visitors.
Contact Form 7 - Contact Form 7 is a tool to manage multiple contact forms.
Forminator - The unbelievable free form plugin you have been looking for
Ninja forms - Ninja Forms is a free form creation solution for WordPress.
Torro Forms - Torro Forms is a drag & drop form builder plugin that is easy to use for administrators, yet flexible to extend for developers.
MightyForms - Powerful forms with lead generation and workflow automation