Looking for a CSS Framework

[eluser]Daniel Moore[/eluser]
I have just checked out YAML (yaml.de/en) but it requires that you place a linkback somewhere on every site on every page that utilizes it, according to it's license. They want 119 Euro before you can legally not include it.

What I'm looking for, is a freely usable, open source solution with no restrictions on the use. Something that will be easy for me to bundle with my CodeIgniter. Something that will not have a lot of difficult to read code or unnecessary code like many solutions seem to have a problem with. A good, clean, robust, powerful, yet simple framework like CodeIgniter, but for CSS.

It must be compatible with all the major browsers, with all the fixes for all the quirks of each browser.

Is there a particular one that anyone recommends?