I have an MSI GeForce4 Ti4400, and I get all of my driver updates from MSI's website. I used to use the ones from nVidia, but too often did I find myself rolling back to an MSI driver just to get video back! Ouch.
Plus, as ShawnD1 said, the features added in to the card like changing the clock are in the MSI driver. MSI is usually about two revisions behind the nVidia website (they're on 41.07 now).
Now, of course, this is true only for nVidia cards, IMO. I'll agree with buddha that Radeons (and ATI in general) often come out with evil drivers in their infancy. Of course, I'm pretty sure that although many companies build ATI cards, they all use the official ATI driver (in other words, no additional writing is done to them) so you can just go for the one with the latest version!