Email Verification Plugin For Wordpress Contact Forms

Wordpress is becoming more and more popular since it is easy to set up and manage. WP owners have to face the spamming situation all day if they don't install the needed anti-spam plugins. I always install Akismet and Accurate Form Data plugins on all of my WP sites and never have a problem with the spammers. Accurate Form Data helps me validating the email/physical address users enter into my site forms (contact forms, registration forms, etc.)

Which plugins you guy use to prevent form spammers?