Gravity Forms is hands down the best contact form plugin for WordPress powered websites. Build and publish your WordPress forms in just minutes. No drudgery, just quick and easy form-building. Select your fields, configure your options and easily embed forms on your WordPress powered site using the built-in tools. That's way more satisfying (and less fattening) than a peanutty candy bar any day.
Demo: http://www.gravityforms.com/