Gentoo. Because everything else is just ****. 
Dude. Gentoo: Its like FreeBSD, but without all the standardisation and stability.
I wouldn't use an NForce motherboard. They're garbage--but that's just a techie opinion. They're perfectly useable for joe user.
I use BSD instead of Linux because its a slower target. Development is slower, more careful and generall (in my opinion) of higher quality. They are more stable because of the slower, more careful development process.
The various BSD platforms are standard. You can move from OpenBSD to FreeBSD to NetBSD and feel reasonably at home. The file system is standardised, and the package and ports systems adhere to that standardization (Debian is strong here too).
Next thing: BSD is BSD derived. It seems like a rather self evident thing to say, but it true. Linux and Solaris share a serious flaw, in my opinion: they both try to mash together the "best" of BSD and the "best" of System-V. In the end, they both end up inconsistent and ill suited for (again, my opinion) serious every day work.
Finally, and most importantly, there are fewer BSD Zealots to deal with than there are Linux Zealots. You won't here your average BSD user cursing your family to its third generation for using a different BSD distribution than he does, or worse a different OS. You will catch this from lots of Linux users though. The BSD user culture is much more laid back, less defensive, less confrontational and more generally helpful.
Keep in mind I don't try to make my boxen into a flashy wunderkind super techie workstation out of Star Trek XXXIV. In fact, it looks and acts a lot like Microsoft Windows on the surface. Underneath the surface, its your average Unix powerhouse.
Other than that stuff, there's really no difference between FreeBSD and Linux.
