Hands down, the best installer of any application I’ve ever used is Office 2007. You just double click the setup.exe file, and a dialog box with two buttons is shown, “Install Office” about twice the size of the next one “Customize”. Push “Install” and a while later, no dialogs, no ads, no sub-installers, no marketing promotions, and no questions asked it’s done. Icons are in place, files open properly and everything works.
Installers are really hard to build and even harder to make this seamless, so hats off to the Office folks. They nailed the out of box experience on 2007.