Apple GUI is not only my favorite desktop paradigm but the most advanced. It contains all the necessary features to work with the environment, however not everybody has an Apple Mac at home or at work, so you have to adapt with the tools you have. Basically you will continue to need windows, at least for the next five or ten years. Hopefully, by then the standards will be implemented so well that if you decide to use OpenOffice instead of MS Office it'll be ok. In my opinion Windows is a great Operating System, IF IT'S VIRTUALIZED.
Besides windows, you need to work with a desktop environment that helps you to achieve your work in a effective way, a desktop environment that lets you do the things quickly and let�s you configure the way you work on it as you need or want.
Linus Torvalds said once:
"This "users are idiots, and are confused by functionality" mentality of GNOME is a disease. If you think your users are idiots, only idiots will use it. I don't use GNOME, because in striving to be simple, it has long since reached the point where it simply doesn't do what I need it to do. Please, just tell people to use KDE."
The two most used desktop environments are Gnome and KDE, before KDE4 I used Gnome but it didn't impact me, it always had some missed feature or some apps had inconsistency with the GUI, nothing like the Apple environment, for example you can always type "CMD + ," to access a program preferences.
In 2006, KDE development team realesed the first developer snapshot of KDE4, one year later it was possible to install KDE4 in some of the linux distros (currently I work with debian so most of the references will be based on KDE4 state in Debian). I like to remember those days as fun and experimental days where some apps worked and others didn't, where sometimes the only option was to launch a gtk app probably because kmail didn't work or because kopete continuously disconnected from Yahoo! accounts. Most of the time I searched for possible solutions, sometimes I found that I had to wait until the next release, for example Kontact (the unified environment for kmail, kaddress book, kalendar, knotes) was available in KDE4.1 release with some issues; KDE4.2 has made it really stable.
Until now some features have not been ported to KDE4 like Koffice which is available in experimental repositories of debian but I can wait because this desktop environment is worth it; it's the closest to a Mac GUI, and sometimes it's even more customizable than a Mac. I have a MacBook at home, but sometimes when I'm out of my office I missed my KDE. It's neat, clean, and it allows a great level of customization. But let's talk about an amazing feature that's available in KDE4 for rpm distros and almost done in debian ones: NEPOMUK
"Nepomuk aims to provide the basis to handle all kinds of metadata on the KDE desktop in a generic fashion. This ranges from simple information such as tags or ratings over metadata extracted from files to metadata that is generated by applications automatically. RDF, the Resource Description Framework, provides the powerful basis to store and query all this data. The goal is to categorize all metadata using clean ontologies to make an automated handling and enrichment of the data possible."
This feature exists in KDE4 but it's working, almost, completly in mandriva, redhat and suse. In debian there are still some issues: I could update the metadata database but I still got some errors when I tried to search for a specific tag; if anyone knows how to solve this in unstable debian, please let me know. :)
Before ending this post I'd like to talk about a post written by Bruce Byfield called "KDE4, the Anti-Cloud Desktop" which has an interesting intro:
"...a vision of desktop-oriented computing in which individual applications are enhanced by Internet resources without being dependent on them, and all online interaction is not funneled through a browser. This vision of the merger of the Internet and the desktop seems a far healthier alternative than accepting online applications..."
The idea behind KDE4 is to allow the user to connect and use the data and applications hosted in the web but without depending entirely on those apps. Instead of that KDE4 proposes that desktop environment take the data and allow the user to work with it from the native applications. In this way the developer and the user have control over the source code and the data. This approach is not possible in the cloud where the source code can only be available to the application owner: "users of online applications are in exactly the same position as users of proprietary applications". Let's wait a few years when the cloud computing idea will be totally exploited and widely used, when the apps can be accessed from the browser and when the browsers become more that mere windows to display web info. Until then my opinion is: if we could keep our favorite application connected to the web running with the data extracted from there, it would be great. Besides if I can use a web application hosted in the cloud and this app gives me all the freedom promoted by FOSS I think this app has a good chance to become the next KOffice.