Like the BS in your posts?
More seriously, both are good OSes and high end PCs are available too. I had a beautiful Aluminium case for my PC when Apple were still casing their kit is plastic.
Thinking one or the other is waaaaaay better than the other is just a bit fanboyish.
I have both here. There's not much in it. Quite literally in the case of a Mac Pro. I have a PC with 8 hard drives in it plus the OS drive + Swap drive. Getting that into a Mac is impossible. Before you mention external HDs I already have 12 ext large drives and I'd like to reduce clutter, not increase it.
I can't comment on pc design, as I've never paid much attention - there seems to be so much choice that there are sure to be those which look awful, and those which look very nice.
My gripe is with Windows which, having used for 10 years+ in its different variations, I grew to truly hate.
For me, and I emphasise I'm talking about my experience only, neither XP nor Vista can hold a candle to the simplicity and ease of use of OS X. Since 'switching' approx 4 years ago, I won't be going back...