Looks like Redlemon found a great animation of Dashboard. Funny, my system doesn't make that watery animation when dragging in new widgets. But my system is 3,000 years old, so it most likely needs a video upgrade to access all the special effects.
Some benchmarks:
Fastest G5 Power Macs versus Fast Windows PCs - CPU Crunching)
Intel Mac Benchmark Smorgasbord
Various Charts
Apple's G5 versus x86, Mac OS X versus Linux
XvsXP (General comparison)
I like the XP taskbar in general, but once it starts filling up with open windows, the window labels become unreadable, until you end up with a row of 30 little unmarked cubes. Filling up each tab with similar windows isn't a great solution either. Apple solves all these issues much more creatively than does Windows, imo. You should really go to a store and play around with one...you can't "explain" why Macs (w/ OSX) are so nifty to use.