I'm dualbooting Mac OS X 10.6 with Arch Linux, with grub bootloader of course, in my Macbook Pro.
I suggest you try Arch linux! It is a pretty good distribution, but you need to be familiar with command line! - The installation is done using command line.
And for my Graphical Interface, I am using WMFS (Window Manager From Scratch), which is a pretty good tiling window manager if you are interested.