reCaptcha by WebDesignBy

Add Google’s latest simple checkbox reCAPTCHA to WordPress default login page. This plugin will help secure your wordpress administration area against brute force hacking attacks using the latest, simple and elegant ‘No Captcha’ reCaptcha checkbox from Google.

This plugin was created because some of the others I tested broke my login page on activation. This plugin is very easy to install and set up. I use it on multiple websites so it is tested regularly.
Simply install, activate and enter your credentials from Google.
https://www.google.com/recaptcha/admin

Requires PHP: 5.3