I started with the Mac later than most long timers of the Mac Community, with my first Mac being an iBook (the last one assembled in Taiwan) running Mac OS X 10.3 Panther, and I had earlier used Jaguar (10.2) in school.
The first major Mac OS X I was really excited about with my Mac peeps was Mac OS X Tiger, and it was the greatest leap in OS X in its time (before Leopard anyway, Microsoft really copied all the new features in Tiger fast and hard). I remembered browsing (on the very first iteration of Safari) John Siracusa’s Tiger review, and being awed by the depth of the OS and the details in the review, which eventually made me want to dive further into the world of Apple and learn more about everything Apple is about.
Sigh. At least we still have ATP.