best distro for me??

If your aim is to learn then I would recommend Slackware, Gentoo and Linux From Scratch. These are among the most involved, they are listed in order of the most user friendly to the least user friendly.

I myself am a Slackware user because I like the flexabiity between doing it the easy way and the more involved way.

If by learning, you mean you wish to know how linux's innards are fit together, and how they work together, then I highly recommend Linux From Scratch. It is easiest to build a Linux from Scratch system from another distribution, and for a beginner I would recommend building from Ubuntu. During installation of Ubuntu, you need to make sure to leave an empty partition for your build. If you have any problems setting everything up, you can always come back here, and I am sure that myself and others would have no objection to helping you.

This is the base book for LFS setup - http://www.linuxfromscratch.org/lfs/view/stable/