Cultofmac.com has posted a great article showing the evolution of OSX over the years. It covers the major new features that were added to each OS release and a desktop screenshot of each. I made my switch to the Mac right between the Jaguar to Panther releases. It’s hard to believe that I’ve been a Mac user now for roughly a decade.
Here’s a screenshot of 10.0 and 10.8 side by side.