Gravity forms is pretty awesome, you can get it here and get a great deal: Gravity Forms. And you'll need your own WordPress site to get it to work. WordPress dot com will not work.
I use Gravity Forms for tons of different things on all the websites I create. It can work as a feedback form like I describe in this video. You can also use it to create a quiz, or a survey. You can even use it to sell products or services right on your WordPress website.
Some of the other features include: multiple page forms, custom fields, you can even schedule a form to be available only during certain times or for a limited number of entries.
In this video I explain how to create a form to gather feedback. I use a form just like this to get feedback from students after they attend a class. This video is part of a tutorial series so I thought I'd share it with you. Feel free to leave any feedback in the comments!
If and when you get Gravity Forms you use this link, you'll get the best deal possible and help me create even more tutorials in the future.