I've heard Linus himself uses Fedora. I'd recommend Gentoo which lets (intends) for you to hand customize your kernel, it's the perfect setting for it (and I've spent many hours squeezing out every last bit of performance for the fun of it).
Naturally Ubuntu is my preferred distro, but you may have trouble if you start hijacking and removing expected kernel features. Gentoo won't complain, and doesn't expected them around to begin with.
