Mac OS X always deserves a special mention in the operating system world, for being the most attractive (arguably) distro around. It is kind of an aspiring product for almost everyone I know - they want to own a Mac at the end of the day! However, exorbitant price and seeking value for money at times limit our aspiration to own a Mac. But, don't worry! Linux can help you create our own Mac! And those who don't know how to customize Linux, there are three distros to help you out.
Pear OS, Elementary OS (though beta stage) and LuninuX OS are closest to Mac OS X from the Linux world. Incidentally all three are Ubuntu derivatives. Both Elementary OS 0.2 Beta and Pear OS 6 are Ubuntu 12.04.1 LTS derivatives with some original elements incorporated whereas LuninuX 12.10 is a Ubuntu 12.10 derivative with a vast array of built in applications.
I did a short experiment to compare across the three. I did a live boot followed by installation in my Asus K54C 2.4 Ghz Core i3, 2 GB RAM laptop with touchpad. A separate 8 GB drive is reserved for this kind of experiment I conduct.
rest here