i personally prefer Zend because the repository is actively supported, it has great components and perform on high load websites good.
check this out Seriously though. code igniter has a lot of fans because of it's ease of use and speed. I've worked with Cake PHP before, and it isn't as easy to use as code igniter, and a bit slower if I recall correctly. However, if you come from a Rails background, you may find cake more intuitive.
Pagination is very important in web application, CodeIgniter has problem with its pagination library..
Though, it will always depends on the scope of the project to choose the framework, which you didn't explained in your posts, but I will prefer Zend Framework. Because it has a strong library/wrapper classes and also has healthy tutorials available on the net.