Just looking for a simple MVC app? Silex (http://silex.sensiolabs.org/)
Want something that's beefier and more rails-inspired? Laravel (http://laravel.com/)
Want MVC but near native PHP performance? PhalconPHP (http://phalconphp.com/en/)
Building an enterprise application with a team of developers? Symfony (http://symfony.com/), Zend Framework 2 (http://framework.zend.com/)
..and I'm only listing the more popular frameworks that I know of that are mature. Every single one of these has full unit test coverage, and most have very clear examples of how to unit test your code.
I like that I can pick from so many frameworks instead. This allows me to choose a framework that fits my problem, instead of fitting a framework around my problem. I find this to be one of the highlights of the PHP community, not one of the downfalls.