When I first got my Apple computer, I thought OS X 10.3 was simply amazing after using Windows my entire life.  Now, I'm using OS X 10.4 and I'm completely blown away.  I love Dashboard!  There's infinate possibilities in such a simple concept as widgets.  I was playing really old games on Dashboard like Frogger and Minesweeper (I still need to download pong and asteroids), and you can look stuff up on Biblegateway.com using a widget.  There's also widgets that show your system status, buddy list, the weather, etc.  I could go on for a very long time.  It's simply amazing.  Another program, Spotlight is pretty cool too.  I've been using it a lot.  It's kind of a search thing that only takes a few seconds to find anything on your hard drive, and it's conveniently located on the taskbar.  To summarize, Mac OS X 10.4 is the same to Windows XP as XP is to Windows 95.