>Aqua from OSX Cheetah

I've never used OSX, but I would guess from screenshots that it didn't do dynamic layered gaussian blur of large screen regions in realtime, which would've been too much for the hardware of the year 2000.

That is true, but don't forget water is the essence of moisture.

Also, those scrollbars were quite impressive for their time.

I always thought they were extremely kitschy, just like the Windows XP window frames.