I was a diehard PC guy for 15-20 years before I bought my first Mac about four years ago. I was looking for a replacement for my shitty old Dell laptop, and initially bought a ThinkPad T-series because by reputation it was the sturdiest laptop available. I found it ergonomically unacceptable, it had a significant built-in bug (it dropped the wireless signal anytime a sound played through the sound card, not exactly a minor problem) and Lenovo's customer service - they pride themselves on their US-based call centers - was HORRIBLE. I ended up returning it and getting a C2D white MacBook with the intention of running Win XP through Boot Camp, since it seemed to be the best-built laptop on the market for the money. It was a loyal friend for years without incident, though I never got around to installing XP because I liked OS X better. I sold it for several hundred dollars when I bought a 13" MBP in the summer of 2009.
As far as I'm concerned the unibody MBP is the best-designed laptop ever built. It's just a pleasure to use, my machine looks and feels perfect after nearly two years of use. The screen, keyboard, and touchpad are the best in the industry. I have Windows 7 Ultimate installed for those rare occasions when I need Windows support, but I use it only about once a month.
I know many Mac haters will criticize anyone who praises Apple products, but the bottom line is that they are beautifully built and a pleasure to use. I find it hard to understand how anyone could handle a MBP, MBA, iPhone 4 or iPad 2 and not be favorably impressed.