Survicate - Collect feedback on your website and find out more about your visitors.
Forminator - The unbelievable free form plugin you have been looking for
Contact Form 7 - Contact Form 7 is a tool to manage multiple contact forms.
Gravity Forms - Gravity Forms is one of the best and easiest contact form plugins to create modern forms for websites powered by widely-used WordPress.
Very Simple Contact Form - This is a lightweight WordPress plugin to create a customized contact form.
Torro Forms - Torro Forms is a drag & drop form builder plugin that is easy to use for administrators, yet flexible to extend for developers.