I was looking at screenshots of Apple.com's former homepages (using the Internet Archive Wayback Machine) and decided to compile them into a slideshow. With the exception of Apple's homepage in 1997, it's pretty remarkable how little the core design has changed.
After 15 years, the layout of Apple.com is still the same: prominently feature the latest product, with 3-4 little boxes below that highlight other recent products and company news. The homepage has become more evident and intuitive each year. Bigger pictures, less copy, bolder text, fewer items to click… It's like a giant billboard. They stuck with a format that worked and continually refined it. [The two biggest changes: they moved the navigation bar to the top in 2000, then gave the entire site a facelift with the introduction of Leopard in 2007.]
It goes without saying that Apple's strength is design, but their homepage deserves credit for being great for so long. Ever since its early days, Apple.com has moved in the direction of being more friendly, focused, simple, and beautiful.