Boring advice here before I give my opwn opinion. Go to an Apple shop and give it a go.
I used to be all PC and never gave MAcs a second thought mainly due to software availability on Macs. BUt now most popular software is compatible on Mac and PC. Anything thats not, you probably have a PC, if not theres bootcamp.
What prompted me to to first look at buying a mac was build quailty. My cousin bought a Macbook pro and I bought a ASUS laptop around the same time. It was a very high spec laptop then(the ASUS). 4 years later, his looks almost brand new, and mine lots of quality issues and just feels so much older than his.
Of course this is just my own experience, they'll be ASUS owners who will be still using their laptops after so many years and it'll be fine and they'll be Mac owners who have had quality issues.
I got my first Macbook (the first 13' unibody ones) last year. And the feel of quality, its just way beyond anything I looked at. I was looking at Sony laptops before Z series before. To be honest maybe the videos of the whole manufacturing process and the tutorial videos on the apple site sold it to me. Sucker? Maybe.. But I've not regretted buying it.
The OS seems to be very slick. Where with Windows, you know after a few years its just going to be doing something in the background which eats up all your resources.
I use my mac a lot and I still use my PC. If you already have a PC, I would suggest trying a Mac.
Apologies for the long reply.
But I hope it helps you in your decision.
EDIT: Macbook screen, picture quality & brightness seemed way above any other laptop also. The trackpad gestures thing actuallly makes using a mouse seem less effective.