I really hate the OS X interface. Converts, did you have trouble getting used to it?
I'm wondering what you don't like about it? Apart from cosmetic differences, pretty much all GUIs are the same (or have arbitrary differences you have to just learn), with a couple of exceptions.
The biggest exception is the handling of "windows" versus "applications." On the Mac, you run an application that creates windows. But a window is not the same as an application, and for the most part closing a window does not close an application.
On Windows, it can be impossible to tell whether you're running two instances of one program, or a single application that has spawned two windows. On the Mac, multiple windows belonging to the same application always belong to a single instance of the same program, and you can control the application itself, as opposed to a window the application has created, through the menubar. This seems like a pointless complication to some Windows users, but the lack of a global way to control a program as opposed to a window has led to weird constructs like "main windows" and, even worse, the multiple document interface (where a program spawns little captive windows within itself) in order to keep things straight. The latest Windows Excel *still* uses MDI. Madness.
Another difference is that most Mac programs don't have the ability to maximize (you can manually make them fill the screen, of course). The zoom button is supposed to expand the window to display its contents, but no further. I think this is a good thing, because just maximizing a window habitually defeats the purpose of a multi-window GUI, makes direct manipulation harder (can't just drag an image from a website to the desktop, for instance), makes task switching slower, etc etc, but people like what they're used to an a lot of people see that lack of maximize as a flaw. A better way to work distraction free is just to hide all the applications you're not using (cmd-option-h).
Also, the preferred way of operating on a Mac is through drag and drop, as opposed to constantly navigating through menus. You can launch a file in a non-default media player like VLC by just dragging to onto the dock icon, for instance, instead of opening the program and going through File->Open, etc. You can do it either way, but drag and drop is much faster. It still amazes me that on XP you can't just drop a file onto a taskbar icon, though maybe Vista has fixed this.
Also expose is awesome. And you can tell I'm on Windows right not because it's too much of a hassle to actually input foreign characters. Can't just do option-e+e.
The biggest thing with learning a new system is that you might not care enough about computers to bother learning something new when what you already know works fine.
