If you choose Gentoo, prepare yourself for a 24-hour install time, possibly with you holding your computer's hand for much of it.
Yoper is my favorite distro, it ran faster than my Gentoo64 config and is ready to go right out of the box. It starts up slower and the kernel is less optimized, but a very good distro to begin learning Linux on IMHO. The init scripts are clean and relatively straightforward, and it's based on Linux From Scratch, and there's plenty of software it comes with/is available from the apt archives.
Install for it is literally a 20 minute process if you know how you're going to setup your hard drive.
It also comes with NVIDIA support, you pretty much just have to check one box on the SaX configuration screen that comes up after the install.
Edit: Gentoo's install is also completely from the command line...it's a good way to learn Linux commands, but if you have problems you'll need to know the ones to fix the prob.