just get linux!!! I used to be an apple fanboy, and still am but I have my ubuntu (actually right now i think it might be kubuntu) machine downstairs and its amazing!!
I've been using Ubuntu on my home desktop/spare system since version 6.x, currently running 8.10. I've used various flavors of Debian, and I have an eeePC running an Xandros variant with KDE. I use an iMac on my desk at work, I carry either a Macbook pro or a Fujitsu Lifebook with Win XP on it. My family uses mostly Mac, but when I get an old X86 machine I usually Ubuntu-ize it. I also have, at work, a very very hyped-up Vista machine for running a complex statistical analysis and visualization system.
You could say I'm platform agnostic. However, I can assure you that Ubuntu is still at least 5 years away from being user-resistant, and might never be ready for mere mortals. Sure, the applications all work well enough, but USB device support is just plain miserable, printing is spotty, fonts are atrocious and don't even get me started about removable media, or more to the point, the entire presentation method of the user's file system space. Say what you will about windows and mac, they have both developed stable metaphors for storage devices, whether local, networked or removable and they have far fewer of the ENDLESS issues with permissions I run into on any and all *nix derived systems.
So, yeah, Ubuntu is a fine option, and if you're willing to put in a month or so to work with it day to day, you really appreciate it, and like I said, I use it for real-live office work when I'm in my home office, so it works for me. I'd NEVER give an Ubuntu system to a novice - never. The support calls would be overwhelming.